Call me stupid, but I've owned the car for 3 months and I didn't discover the trunk key hole until tonight! Any other weird things you guys wanna share that you may have discovered about the car that may not be known right away?

For my previous car (Rav4), there were lots of secret storage compartments. I'll start the list.

1. Keyhole on underside of trunk handle.
2. ....

 

Just noticed the lower part of the back seat can be flipped forward, so the back of the back seats can be folded completely

 

3. the car has the TV input

 

With the transmission in the C mode, it will hold itself without your foot on the brake if the nose is up.

Pointing the key at the infrared window on the drivers door handle and holding the lock button down will close the windows and sunroof.

Holding the recirculate button on the AC for a second will close all windows and sunroof. Pressing it again will send the windows and roof back to their previous open positions, even partly open.

Pressing the reset odo button on the instrument cluster 3 times when key is switched on to start will display battery voltage and liters of oil in the engine.

Holding the CDC button on the radio for a second will enter tha AUX input mode. Allows walkman or mp3 playback through a jack in the glovebox. (optional cable needed)

Pushing the red button on the drivers side hood support allows the hood to be raised to nearly vertical. As with all German cars, easy does it, don't drop or slam anything.

Three buttons on the lower left of the mirror can be programmed to:

1. Open your gates
2. Set house and yard lights to romantic mood.
3. Turn on spa and sauna.

On some cars, the center arm rest can be opened from the left or right.

On some sedans a button under the center vents can electrically lower the rear seat headrests.

If you miss a payment, Mercedes-Benz Financial will send a magician to make your whole car disappear.

 

Apparently, my little key hole secret is nothing compared to what you just told us. mp3 playback in the glove box??? where??
Can I really make the car disappear??...hehe, you're funny.

I heard that cable in the center console is connected to the a/c and therefore we can keep stuff in there cool if the a/c is on. Is that true? If not, what's the cable for?

 

You gotta state your model year. Not all secrets work with every year especially when comparing 2001-2004 (pre-facelift) and 2005+!

Off the top of my head... this is for 2003.
1. Glovebox has a hidden compartment for sunglasses, it's on the other side of the door. Above the storage rack/CDC is a clip where you can put a tire pressure gauge.
2. REST mode can be activated on 2003+ by hitting the AC-Off button when the ignition is off. (found this by accident) Looks like they just renamed the button from MY2002 but didn't delete the feature. This is when the fans still blow air into the cabin when the ignition is off. Too weak for any real use though imo.
3. Dyno mode - push reset button 3 times with key in position 2. Then use the arrow keys. Can see battery voltage, VIN, engine build, amount of oil, and can turn on Dyno mode.
4. Coupe drivers - if you replace your fob case with a sedan one (3 buttons instead of 2), you will also get a trunk release feature. The hatch is too heavy to fly open though (which is probably why they deleted this button).
5. Centre console has slots for gas cards. Kinda useless though, the ones I have just fly out.
6. Coupe back seat headrests have 2 available "up" positions. Might be the same for sedan.
7. Pushing 4 or more steering wheel buttons simultaneously will activate the horn. (don't ask me how I figured this out)
8. Driver's seat floor carpet has 2 strange bumps. These are for floormat clips. You can buy these clips separately from the Parts department. I personally attached them to my all-season mats so they don't slide around like crazy. (with some help from a pair of scissors) A WAY better option than the OEM clamp + spike option!
9. Gas pedal has "kick-down" button when you floor it.

 

I have a 2001 C320 Elegance sedan (for now) and find these discussions very interresting. I even ran out to my car a few times to try some of the "dyno" and "kick-down" stuff. Didn't think I had such a smart car. In follow up to item 3. Dyno mode. How many litres of oil is the C320 supposed to take? The dealers in South Africa were not sure and I continuously got "add 1.0 oil" when I took measurements. When I did the 3-times "thing", I saw there was 5.6 litres oil. This ok? What oil would you recommend for mileage 302,699km?

I'm buying a 2006 C350 next year and want to do some minor mods to it. Would a Kleemann supercharger as for the C320 fit (or is there a newer one)?

 

Wow... pretty cool list. These are all features that aren't even in the manual?

 

saw it yesterday while I was washing my car...pretty cool features you guys mentioned...

 

Not secrets really, more like tips...

2002 C230K coupe :

1. Need switched igintion power to hardwire a radar detector so it turns on/off with the engine? Don't run a wire all the way from the back like everyone else says you have to. The OBD2 port in the drivers side hush panel (black plastic panel by yer feet) has the wire you need. Since the radar detector doesn't need much juice to make it work, no extra or larger fuses are needed.

Using a "test light", turn the ignition to the run postion without starting the car and touch each pin until it lights up. Then shut the ignition off to make sure the light goes out. If it does, you have the correct pin. Simply flip the connector over, figure out which wire it is and tap into it. VIOLA, switched power and no need to hassle with running it from the trunk area.

2. Need power for an aftermarket amp? The fuse panel located behind the small door on the left of your trunk has and 8 AWG wire suppling power to it that comes directly from the battery. Attach an 8 AWG eyelet to 6" - 8" of 8 AWG wire, then connect your fuse holder and install the same size fuse that your amp has and run 8 AWG from the fuse holder to your amp. No need to run it all the way from your battery, drill a hole in your firewall and run the wire all the way back.

 

how exactly do i tap the power from the obd port?
im currently not running a wire all the way from the back
im tapping the fuse box...but they're all constant power sources
so its annoying cuz i have to manually shut off the radar detector

 

i love the recirculate button that will open/close the windows...

 

as far as i understand ... the lower arm-rest compartment have a swith to the inner side wall ... able to let u direct the a/c on and off to the compartment ...

i think we forget to add the throttle re-set feature which is quite a neat one to have ...

btw ... the aux function is cool ... what year model was that ... unfortunately i already got my ipod connect via connect2 to the antenna ... which it gives reasonable sound quality but no way as good as the cd from the CD10 audio ...

and what else ... i can't think of any ...

 

should rename this threat "Easter Eggs"

but ya good thread lol

 

For the AUX input you need a 2005 up car with a CDC button on the head unit. There is a cutout in the right side of the glove box for the cable you need to buy from the dealer. It plugs into the wire harness in the right door sill. There is a thread with pictures on zactly how to do it.

The cable in the lower center console is mostly prewiring for the optional telephone cradle. The lower compartment gets cool because the air duct for the rear seat vents runs under there.

 

The cable is for the hands-free cell phone connection. There is a vent in the lower compartment of the center console that is connected to the a/c. During the summer I keep a bottle of water in there and it can go from hot to fairly cool in about 15 minutes.

 

i don't know if c230/240 has the a/c in the center console, but c320 does have that feature.

 

The key hole on the trunk of my 03 C230 could be used to manually lock the trunk (interior release and remote transmitter would not open it - only the blade could be used). The key hole on my 05 C230 can only be used to open the trunk in the event of a dead battery. I frequently have my laptop and various documents in my trunk, so I miss not being able to lock anything more than the glove box with my key.

If anyone knows how to manually lock the trunk on the 05 + C sedans, please provide instructions.

 

how do i check how many miles i have left to drive or how many gallons i have left in the car? I tried pressing the reset button 3x and it doesn't work. which setting/display do i need to be in? any single one in particular?...or just make sure the key is in position 2? Can the car be running?

 

theres this one...

When Driving quick towards a wall, airbags will deploy. If driving fast enough, car can be replaced!

 

you can tap the acc wire from the cigarette lighter socket. Centre pin positive.

 

when you step on the brake, the gas cut off

so is like you can't press on 2 padal at once

i tried when i was bored i wanna speed up with just a little brake light comes on

 

i know the c240 has the a/c in center console. very useful for my eyedrops.

 

haha, lance ya going on a latenight posting spree?

 

In Drive, if you press the gas pedal twice, flames will come out of the tailpipe, the car does a wheel stand, and you get a sudden burst of boost.