With my new Black Series Spoiler installed, my radio upgrade is next. I was scoping out where to run the positive wire from the battery to the trunk, but I couldn't find a obvious solution. I can see the factory positive wire goes across the engine compartment and to the fuse box, but I'm not sure it there's an opening into the passenger compartment. I could drill through the firewall, but I'll only do that as a last resort. So where did your installer place the positive wire?

Also, did they use the factory speaker wiring (tapped from the AMP) or did they run their own speaker wires?

Since there is no W209 DIY radio installs, I plan to write up a how-to once the project is done and share my lessons learned.

It depends on what gauge wire you are going to be running.. I ran a 4gauge wire from the battery, across the back of the engine ( along the A/C pipes) into the fuse box, and out the backside into the drivers dash.

Pull out the underside of the drivers dash, and get out a metal coat hanger, fish your way through.

Pull up all your door trim and run your PW with the rest of the wires....all the way to the trunk, hiding the wires behind the trims.

Thanks for the info Supafly! I knew there had to be a way without drilling the firewall.

By the way, did you install that Alpine 505 DD screen you mentioned in the other post? How about your decision on the 13.5" or the two 10" JL's? How did you access the 6X9's in the back?

Yah, it took a while to figure it out, i also didn't want to drill into my firewall. You have to notch the fusebox on the side enough so that the powercable will sit flush into the box...Just be careful, when you fish your line, that you dont poke/pull any wire looms.

I got the 505 placed on order, but im kinda having second thoughts...might go with the 203, i think it would be better as they already have them in stock.
Im going with 2 10" subs and in 2 seperate custom enclosures as it will maximize my trunk space fitting into the side pockets.

To get to the 6x9s, pull up the speaker covers, take out that shotty 10" sub, mark and dremel out your holes from the bottom because theres not enough clearance to work from the top...I ran the wires inside the metal tubes down the sides and out to the amps.

I ran the PowerCable down the drivers side, and the rest of the audio lines down the passenger console, across the passenger floor mat ( where the foot-lining meets the middle lining) and into the passenger door trim. Then all the way back to the trunk, following the same procedures as the PW.

The only problem i ran into after the audio install is that i lose the option of controlling the audio from the HUD screen....maybe i'll invent something to make it work..

i took my car to a pro, Gold Star Audio in Irvine, ca. they are super knowledgeable and don't charge an arm and a leg. i got my kenwood head unit and alpine drop down dvd installed for a really reasonable rate, much cheaper than my time to do it myself. i dropped it off before work and picked her up at lunch and it was perfect.

I've done that in the past, and some installs can easily rocket past 1500 for a basic install running 0-1 gauge wire....try doing it on your own sometime, it would be a learning experience, and you will feel better by accomplishing a mod with your car.

i wash and detail my car every week, so i know how it feels to do something yourself that others would charge a lot for.

when i was 17 me and a buddy tried to completely rewire and setup my Jetta with 2 subs and all new speakers, amps and wiring. it was the biggest mess ever and took 1-2 months. i learned the hard way to take that kind of stuff to a pro, its worth the money for me to have it done right and quickly.

not saying i would do the same thing again if i tried it over, but right now its just makes more sense for me to get that type of stuff done by an expert instead of hours and hours of my valuable time where i could earn much more than 1500 dollars.

its just a time/value analysis and personally i value my time more than saving the money in this particular situation. maybe for you it makes sense but for me it doesnt.

I agree with both of you. I like the sense of accomplishment when I do a job myself, but at the same time, if the job is way over my head, I'll look to the pros to get it done. In this case, I will do it myself for these reasons:

1. The Pros will do the install THEIR way, which is not all that bad. But if a fuse is blown and I have to fish all over trying to figure where they put them or worse force to go to their shop again; I waste more of my time. Besides, it won't take me more than a day to do it (I have everything ready to go) and I have everything mapped and planned out.

2. I've done the research and the only thing I couldn't figure out was the Power Wire. I have the W209 repair DVD, all the harnesses, face plate, and experience to do the job well. It really isn't a difficult job (the repair DVD helped me figure that out).

3. Cost - I think Supafly is right on the estimated cost for a professional install. Since the shop is liable for anything they break, they will charge top dollar for the install on a Mercedes.

4. Sense of Pride/Accomplishment - NO ONE will take care of my car more than me, so I will not cut corners when doing the install. And when someone compliments my system, I will be proud to say that I did it myself.

5. Share my knowledge - Like Supafly, I can help fellow MBworlders on their installs when they have questions. This is the best Mercedes Benz Forum and I will be honored to be able to share my knowledge.

Supafly, don't forget to take pics when your done with the install!

I'm a hands on person, plus I like to know every thing that has been done so that I know where to troubleshoot if there issues later down the line. I've done installs on all of most of my vehicles (trailblazer, suburban, S10, HHR, Berretta, etc.) since the late 80's.

I want to do a total replacement like what you all are doing. I've just been hesitant since I've not worked with a vehicle that has the fiber optics and integration that the MB does.

I will definitely appreciate any DIY info and pics that you share!!!

By bypassing the stock radio and amps, you can bypass all the fiber optic stuff. You will lose the steering wheel volume control and the HUD CD track changer, but you gain a kick *** sound system! I just have a 6 disc CD changer now, but I'm going to have navigation, bluetooth,7" touch screen, DVD playback, 3G iphone control, and HiFi sound. Its going to be great!!!!!

Definitely keep us up to date with your progress. I'm thinking about taking this on sometime later this year......