Pretty easy, but a little hairy at times. Using the following parts, you can also do this installation

Q6820912 ($160),
Q6820965 ($110),

NOTE: these two parts are no longer in the central warehouses, so you
have to get lucky finding these parts at local dealers or dealerships that will ship to you.


Bluetooth puck
67875878 ($150 used ebay)

Picture right after I was finished with the install


Picture after I put all the liner back


I have attached the installation directions. There are some minor differences. At times I was second guessing myself during the install, my first try nothing powered up. Then I realized that I had put one of the fiberoptic cables into the wrong slot. It worked beautifully the second time. No coding, and I didn't need to do anything at the transmission tunnel.

Anyone who wants to do it, I know of two dealers that might have these parts and also I can help chime in if you get stuck. I am not really mechanical, so with some patience anyone can do this. It is definitely not worth the $2000 people have been paying especially when the parts are not even that much.


2005-09 CLK Coupe BT Install (1).pdf

thanks for the info and pics. I have C320 sedan 2005 and going to do same. I was wondering what cell handset are you using and is it BT or no?

It's an iPhone 4. Bt or no? I don't think I would have gone through this effort if no.

I read thru the pdf instructions and this seems far from "easy". I'm pretty mechanically and technically inclined and even I thought this was very complicated.

Once you get in there it makes more sense. After pulling back the trunk lining, you see all the parts that are shown in the pdf. I read through the pdf and really didn't understand that well, but I pulled out the trunk liner. After I was able to identify the working areas in the pdf, it was easier. Also, I didn't have to find the exposed transmission tunnel and the BT ended up working.