Folding rear seat
Does anyone know if there is some kind of control to keep someone from doing that?
I didn't take any pics but if anyone else is thinking of trying this, I could write up a DIY.
FYI- If you are ordering a salvage seat, see if you can also get the rear deck and trunk mat(specifically the plastic part snapped on the the mat) thrown in or at a resonable price as they are slightly different. I just left my rear deck (with the empty seat belt slot) in place as it would take a very keen eye to notice it. I also just carved off about a half inch of the rigid plastic piece to allow the seats to operate properly.
Now that I have my upgraded mirror and folding seats installed, I am completly happy with my bare bones, manual transmission car...well maybe another 70 HP would be nice....
I didn't take any pics but if anyone else is thinking of trying this, I could write up a DIY.
FYI- If you are ordering a salvage seat, see if you can also get the rear deck and trunk mat(specifically the plastic part snapped on the the mat) thrown in or at a resonable price as they are slightly different. I just left my rear deck (with the empty seat belt slot) in place as it would take a very keen eye to notice it. I also just carved off about a half inch of the rigid plastic piece to allow the seats to operate properly.
Now that I have my upgraded mirror and folding seats installed, I am completly happy with my bare bones, manual transmission car...well maybe another 70 HP would be nice....

I did not hook up the wiring harness in my install. I simply cut the wiring harness off my locking mechanism as I will just give the seatbacks a little tug if I am not sure if the lock engaged.
1. Remove the trunk mat and plastic piece attached to the mat and set aside. The plastic piece has two fastners that need to be popped out.
2. Pull up on the front edges of the rear seat to release the pinch clip.
3. Hold the front of the seat bottom up while you press down and rearward near the back corners of the seat bottom. There is a rear facing “hook” that holds the seat down so you need to put a bit of downward pressure to hold the seat down and shove backwards at the same time.
4. Remove two bolts from the bottoms of the seat backs and two star head screws from the bottom of the “wings” of the seat backs.
5. In the trunk, there are two holes on the brace running under the rear deck (rear shock tower brace). You have to press a release through these holes to release a locking mechanism to allow you to lift the seat up slightly and then out.
6. Once you have the seats out, you need to pop out the two trim fasteners (with rubber grommets) to allow access under the rear deck. I did not change out the rear deck as it seems to be a ton of work to simply get rid of a not very noticeable plastic slit for the rear seat belt. (the folding seat belts are seat, not rear deck, mounted) Once you have the fasteners removed, use a block of wood, etc to hold the deck up and allow access to the seat belt reel and bracket mounting area.
7. Remove the seat belt reel mechanism from the rear deck with a socket. You will also need to remove the bracket on the lower seat/floor panel to allow you to remove the seatbelt from the car. Note how the brackets are located on the seat/floor panel.
8. Remove the two seat latching mechanisms with a star driver.
9. Reinstall the two new mechanisms with a star driver being sure to route the cables through the holes in the rear deck brace
10. Insert the cable ends into the plastic release handle mechanisms and make sure they are functioning properly. Pop the release handles into place under the rear deck. My plastic clips were mostly broken off so drilled a small hole (near the middle of the handle but away from the moving parts) and used a short drywall screw to secure to the underside of the rear deck.
11. Reinstall the two rear deck fasteners with the rubber grommets.
12. Place both sides of the seat backs roughly into place in the car. You will need to connect the two sides of the seat together with a single bracket/hinge before you place them into position. This is a little tricky as the seats need to be, and stay, pretty well aligned when you lock the bracket down and are a bit big to easily move into place.
13. Once you have the seats connected with the center bracket/hinged and in place, you can use two 10 mm bolts on each side and two in the middle to lock the seat backs in place. Make sure once everything is locked down, that the seats operate well as there is a bit of “slop” allowed.
14. Rebolt the center seatbelt brackets into place in the same location as they were when you removed them earlier.
15. Insert the “wing” panels into place and lock down with the star screws.
16. Install the cushion “bar” under the seatbacks. It should have black plastic brackets facing down and pointing forward and simply slide down over “screws” protruding from the floor. It locks in place as much with pressure from the upper and lower seats as it does from the brackets.
17. Pop the lower seat panel back into place. My replacement lower seat panel was a bit rougher than my original so I just reinstalled my original as they are the exact same part.
18. Using a fine toothed jigsaw or similar, cut off about ½-1 inch of the leading edge of the plastic piece that snaps onto the trunk liner. To get this looking good, it will take a few cuts so just take your time and think of it as art…lol. This may be a piece that you would want to order and replace from MB as it shouldn’t be too expensive.
19. Reinstall plastic piece with the two fastners, clip the trunk mat on to it and you are done.
I think that about covers it but if anyone has additions or feedback, feel free to add anything helpful.
Last edited by C300Sport; Jun 28, 2012 at 10:48 AM.

Is there any chance to place pics how the car looks after the retrofit with the seats up (from the trunk view) and down (as many as possible with mounting spots)? I need to do this in my car asap, I still don't understand how could I miss that on the options list as well as the cruise control with which i'm fighting as we speak..
Once again congrats!
The Best of Mercedes & AMG

Special thanks goes to C300 and Nuru for providing more information than I could ask for, it made the whole project a lot easier. I also had much help from a friend at MB Service in Hilden, Germany, who provided me with all the part numbers neccesary to do the install. I had some issues mainly because my salvage seats came without the middle bottom locking mechanism which ment I had to buy a lot of genuine parts from MB. Anyway, the DIY written by C300 is a masterpiece and it really covers it all. My modification was that I just removed the middle seat belt from the new seats since it was black and I needed a beige one, it was way over 200$ just to replace it since the salvage seats i got came in dark grey. If anyone is interested in install pictures I can do some uploading.
Thanks everyone for the help! Now I have the car of me dreams including the new leather interior which I'll be showing in a new thread

Special thanks goes to C300 and Nuru for providing more information than I could ask for, it made the whole project a lot easier. I also had much help from a friend at MB Service in Hilden, Germany, who provided me with all the part numbers neccesary to do the install. I had some issues mainly because my salvage seats came without the middle bottom locking mechanism which ment I had to buy a lot of genuine parts from MB. Anyway, the DIY written by C300 is a masterpiece and it really covers it all. My modification was that I just removed the middle seat belt from the new seats since it was black and I needed a beige one, it was way over 200$ just to replace it since the salvage seats i got came in dark grey. If anyone is interested in install pictures I can do some uploading.
Thanks everyone for the help! Now I have the car of me dreams including the new leather interior which I'll be showing in a new thread

OK, Lets do this! :-)
First of all you will need to organize a few things which are neccesary to do this modification. I don't know what is the color of your interior, but the best thing would be to get rear folding seats in the same color to save money on extra upholstery change, as well as the middle seat belt, the plastic covers around the neck rests, the cover for the back armrest and the cover around the middle seat belt. What you're looking for is rear seats, a panel which goes between the back rest and the rear bench, side panels. The bench is the same, but it's usually something you get as a full set. On this picture you can see all the elements you need:

Next thing we want to de before starting is completing all the other parts. Here's a list for you with some explanation, pics later on:
1. Screws. Get 6 screws, 10x1.5, you'll need them to attach the new seats, Mercedes has changed the diameter of the screws depending on wheter you have folding or non-folding rear seats. Absurd, but yes, it's true, so be prepared and pick those up

2. Middle locking mechanism, part number: A204 920 00 24. This is the most important part, without it you can't mount the seats, I had to get a new one, costed me about 25US$
3. Two release handles, which will be mounted in the trunk, part numbers: A204 920 01 64 LEFT SIDE, A204 920 02 64 RIGHT SIDE, should be around 7$ a piece
4. Two new locking mechanisms, which come with a wire which you'll later connect to the release handles, part number: A204 920 09 72, I got one used but fine for around 35$, the second one I had to get from the dealership, 70$
5. I wanted it to look OEM so I also got the new plastic cover in the trunk and the new trunk mat as you could see in my thread, The plastic part number is A204 690 46 30 and the trunk matt is A204 680 14 42 or 15 42 or 02 42, they are all the same, I went with 15 42 because that was the one I found in best value plus the seller thrown in the plastic cover so it was a great deal for under 80$, just had the new trunk matt cleaned so it looks brand new now

These are the parts withouth which you won't do anything. Now. moving on to the best part which is the DIY. I'll just copy-paste the one made by C300 on the forum, it's great, it covers everything but I'll add some of my hints and tips. Here we go:
DIY:
1. Remove the trunk mat and plastic piece attached to the mat and set aside. The plastic piece has two fastners that need to be popped out.
2. Pull up on the front edges of the rear seat to release the pinch clip.
3. Hold the front of the seat bottom up while you press down and rearward near the back corners of the seat bottom. There is a rear facing “hook” that holds the seat down so you need to put a bit of downward pressure to hold the seat down and shove backwards at the same time.
4. Remove two bolts from the bottoms of the seat backs and two star head screws from the bottom of the “wings” of the seat backs.
5. In the trunk, there are two holes on the brace running under the rear deck (rear shock tower brace). You have to press a release through these holes to release a locking mechanism to allow you to lift the seat up slightly and then out.
6. Once you have the seats out, you need to pop out the two trim fasteners (with rubber grommets) to allow access under the rear deck. I did not change out the rear deck as it seems to be a ton of work to simply get rid of a not very noticeable plastic slit for the rear seat belt. (the folding seat belts are seat, not rear deck, mounted) Once you have the fasteners removed, use a block of wood, etc to hold the deck up and allow access to the seat belt reel and bracket mounting area.
7. Remove the seat belt reel mechanism from the rear deck with a socket. You will also need to remove the bracket on the lower seat/floor panel to allow you to remove the seatbelt from the car. Note how the brackets are located on the seat/floor panel.
8. Remove the two seat latching mechanisms with a star driver.
9. Reinstall the two new mechanisms with a star driver being sure to route the cables through the holes in the rear deck brace
10. Insert the cable ends into the plastic release handle mechanisms and make sure they are functioning properly. Pop the release handles into place under the rear deck. My plastic clips were mostly broken off so drilled a small hole (near the middle of the handle but away from the moving parts) and used a short drywall screw to secure to the underside of the rear deck.
11. Reinstall the two rear deck fasteners with the rubber grommets.
12. Place both sides of the seat backs roughly into place in the car. You will need to connect the two sides of the seat together with a single bracket/hinge before you place them into position. This is a little tricky as the seats need to be, and stay, pretty well aligned when you lock the bracket down and are a bit big to easily move into place.
13. Once you have the seats connected with the center bracket/hinged and in place, you can use two 10 mm bolts on each side and two in the middle to lock the seat backs in place. Make sure once everything is locked down, that the seats operate well as there is a bit of “slop” allowed.
14. Rebolt the center seatbelt brackets into place in the same location as they were when you removed them earlier.
15. Insert the “wing” panels into place and lock down with the star screws.
16. Install the cushion “bar” under the seatbacks. It should have black plastic brackets facing down and pointing forward and simply slide down over “screws” protruding from the floor. It locks in place as much with pressure from the upper and lower seats as it does from the brackets.
17. Pop the lower seat panel back into place. My replacement lower seat panel was a bit rougher than my original so I just reinstalled my original as they are the exact same part.
18. Using a fine toothed jigsaw or similar, cut off about ½-1 inch of the leading edge of the plastic piece that snaps onto the trunk liner. To get this looking good, it will take a few cuts so just take your time and think of it as art…lol. This may be a piece that you would want to order and replace from MB as it shouldn’t be too expensive.
19. Reinstall plastic piece with the two fastners, clip the trunk mat on to it and you are done.
So that covers everything you'll need to do. Now the pics!
This is how it all should look like after you finish, except the rear upper deck which is not worth changing, the next picture shows how mine looks like after the install

This one show my upper deck as well as the bottom plastic before changing it to the new one which I described you earlier when listing all the parts.

Now, the locking mechanisms and the release handles:


The next thing would be the middle locking mechanism and its attachment points as well as the mounting points to the seats:
This is when it's opened:

Now closed (you need to get a small screw to lock it permanently, after you do it you'll see the place where it should be placed, you can see the small hole at the end of the piece which is movable on the previous picture):

This is where you need the 10x1,5 screws I mentioned before, as well as the seats mounting points on the other side, two on each, didn't take a picture, but it's super-easy to find them


Here are the pictures of the new plastic cover and the new trunk mat which I got from a salvaged car which fits the rear folding seats car, I took it to a auto-detailing garage and they made it look brand new and this is how it looks from the trunk after the full conversion:

So I think that should do it. I followed only the DIY and bought a grey couch because after I've finished I immediately went to make a custom leather upholstery, but the grey couch ment I got rid of the middle seat belt (It was black and way over 250$ to replace it back to beige) and had to replace all the plastics to beige (extra costs..)
If you have any further questions I will be more than happy to help! Just take your time, collect all the things I've listed and that should do it

TOP TIP: When looking for rear folding seats ask for the middle locking mechanism, maybe you can get it thrown in? Also very important: remember only to look for SEDAN folding seats, the ones from a station wagon won't fit since a station wagon doesn't have a rear deck and the locking mechanisms are in different place, but i gues that in the US you only have sedans? I don't know. Anyway, hope to hearing from you and as i've said: feel free to ask about anything! :-)
Cheers,
Maciek
Last edited by TOKI; Jul 18, 2013 at 03:04 PM. Reason: language correction

To be honest, I have only noticed the seat belt slot when I am wiping the car down and am glad I didn't spend the extra time, money and effort.
I did this mod yesterday on my 2011 C300. Using www.car-part.com I found a folding rear seat from a 2012 C250 at a local salvage yard over the weekend, with the release cables/handles and mounting hardware (no plastic trunk liner or trunk mat) for $280.
Thanks again! Couldn't have done it as easily without you.

OK, Lets do this! :-)
First of all you will need to organize a few things which are neccesary to do this modification. I don't know what is the color of your interior, but the best thing would be to get rear folding seats in the same color to save money on extra upholstery change, as well as the middle seat belt, the plastic covers around the neck rests, the cover for the back armrest and the cover around the middle seat belt. What you're looking for is rear seats, a panel which goes between the back rest and the rear bench, side panels. The bench is the same, but it's usually something you get as a full set. On this picture you can see all the elements you need:

Next thing we want to de before starting is completing all the other parts. Here's a list for you with some explanation, pics later on:
1. Screws. Get 6 screws, 10x1.5, you'll need them to attach the new seats, Mercedes has changed the diameter of the screws depending on wheter you have folding or non-folding rear seats. Absurd, but yes, it's true, so be prepared and pick those up

2. Middle locking mechanism, part number: A204 920 00 24. This is the most important part, without it you can't mount the seats, I had to get a new one, costed me about 25US$
3. Two release handles, which will be mounted in the trunk, part numbers: A204 920 01 64 LEFT SIDE, A204 920 02 64 RIGHT SIDE, should be around 7$ a piece
4. Two new locking mechanisms, which come with a wire which you'll later connect to the release handles, part number: A204 920 09 72, I got one used but fine for around 35$, the second one I had to get from the dealership, 70$
5. I wanted it to look OEM so I also got the new plastic cover in the trunk and the new trunk mat as you could see in my thread, The plastic part number is A204 690 46 30 and the trunk matt is A204 680 14 42 or 15 42 or 02 42, they are all the same, I went with 15 42 because that was the one I found in best value plus the seller thrown in the plastic cover so it was a great deal for under 80$, just had the new trunk matt cleaned so it looks brand new now

These are the parts withouth which you won't do anything. Now. moving on to the best part which is the DIY. I'll just copy-paste the one made by C300 on the forum, it's great, it covers everything but I'll add some of my hints and tips. Here we go:
DIY:
1. Remove the trunk mat and plastic piece attached to the mat and set aside. The plastic piece has two fastners that need to be popped out.
2. Pull up on the front edges of the rear seat to release the pinch clip.
3. Hold the front of the seat bottom up while you press down and rearward near the back corners of the seat bottom. There is a rear facing “hook” that holds the seat down so you need to put a bit of downward pressure to hold the seat down and shove backwards at the same time.
4. Remove two bolts from the bottoms of the seat backs and two star head screws from the bottom of the “wings” of the seat backs.
5. In the trunk, there are two holes on the brace running under the rear deck (rear shock tower brace). You have to press a release through these holes to release a locking mechanism to allow you to lift the seat up slightly and then out.
6. Once you have the seats out, you need to pop out the two trim fasteners (with rubber grommets) to allow access under the rear deck. I did not change out the rear deck as it seems to be a ton of work to simply get rid of a not very noticeable plastic slit for the rear seat belt. (the folding seat belts are seat, not rear deck, mounted) Once you have the fasteners removed, use a block of wood, etc to hold the deck up and allow access to the seat belt reel and bracket mounting area.
7. Remove the seat belt reel mechanism from the rear deck with a socket. You will also need to remove the bracket on the lower seat/floor panel to allow you to remove the seatbelt from the car. Note how the brackets are located on the seat/floor panel.
8. Remove the two seat latching mechanisms with a star driver.
9. Reinstall the two new mechanisms with a star driver being sure to route the cables through the holes in the rear deck brace
10. Insert the cable ends into the plastic release handle mechanisms and make sure they are functioning properly. Pop the release handles into place under the rear deck. My plastic clips were mostly broken off so drilled a small hole (near the middle of the handle but away from the moving parts) and used a short drywall screw to secure to the underside of the rear deck.
11. Reinstall the two rear deck fasteners with the rubber grommets.
12. Place both sides of the seat backs roughly into place in the car. You will need to connect the two sides of the seat together with a single bracket/hinge before you place them into position. This is a little tricky as the seats need to be, and stay, pretty well aligned when you lock the bracket down and are a bit big to easily move into place.
13. Once you have the seats connected with the center bracket/hinged and in place, you can use two 10 mm bolts on each side and two in the middle to lock the seat backs in place. Make sure once everything is locked down, that the seats operate well as there is a bit of “slop” allowed.
14. Rebolt the center seatbelt brackets into place in the same location as they were when you removed them earlier.
15. Insert the “wing” panels into place and lock down with the star screws.
16. Install the cushion “bar” under the seatbacks. It should have black plastic brackets facing down and pointing forward and simply slide down over “screws” protruding from the floor. It locks in place as much with pressure from the upper and lower seats as it does from the brackets.
17. Pop the lower seat panel back into place. My replacement lower seat panel was a bit rougher than my original so I just reinstalled my original as they are the exact same part.
18. Using a fine toothed jigsaw or similar, cut off about ½-1 inch of the leading edge of the plastic piece that snaps onto the trunk liner. To get this looking good, it will take a few cuts so just take your time and think of it as art…lol. This may be a piece that you would want to order and replace from MB as it shouldn’t be too expensive.
19. Reinstall plastic piece with the two fastners, clip the trunk mat on to it and you are done.
So that covers everything you'll need to do. Now the pics!
This is how it all should look like after you finish, except the rear upper deck which is not worth changing, the next picture shows how mine looks like after the install

This one show my upper deck as well as the bottom plastic before changing it to the new one which I described you earlier when listing all the parts.

Now, the locking mechanisms and the release handles:


The next thing would be the middle locking mechanism and its attachment points as well as the mounting points to the seats:
This is when it's opened:

Now closed (you need to get a small screw to lock it permanently, after you do it you'll see the place where it should be placed, you can see the small hole at the end of the piece which is movable on the previous picture):

This is where you need the 10x1,5 screws I mentioned before, as well as the seats mounting points on the other side, two on each, didn't take a picture, but it's super-easy to find them


Here are the pictures of the new plastic cover and the new trunk mat which I got from a salvaged car which fits the rear folding seats car, I took it to a auto-detailing garage and they made it look brand new and this is how it looks from the trunk after the full conversion:

So I think that should do it. I followed only the DIY and bought a grey couch because after I've finished I immediately went to make a custom leather upholstery, but the grey couch ment I got rid of the middle seat belt (It was black and way over 250$ to replace it back to beige) and had to replace all the plastics to beige (extra costs..)
If you have any further questions I will be more than happy to help! Just take your time, collect all the things I've listed and that should do it

TOP TIP: When looking for rear folding seats ask for the middle locking mechanism, maybe you can get it thrown in? Also very important: remember only to look for SEDAN folding seats, the ones from a station wagon won't fit since a station wagon doesn't have a rear deck and the locking mechanisms are in different place, but i gues that in the US you only have sedans? I don't know. Anyway, hope to hearing from you and as i've said: feel free to ask about anything! :-)
Cheers,
Maciek
I no its an old thread but any chance you could send me the completed picture, they are no longer showing? Also im a bit unsure of the x6 screws you said i needed? Everything else ordered and coming next week.
thanks Nick
Here is my input for anyone else -
x6 M10 bolts used but I also used x2 M10 nuts on the middle locking mechanism.
Also didn't need the Middle locking mechanism because my seats came with it already attached so managed to send back the 1 i ordered.
When fitting the x2 wings I needed 2049230214 Rear Seat Seat Cushion Pad Bracket Clips, for the top on the wing to clip in to.
Didn't need to order the plastic cover in the trunk / boot or even chop down also the original fitted fine also well as the trunk matt.






