The mCar device connects to the MOST fiber optic system in your car. It is installed in place of the factory CD changer and provides Bluetooth hands-free calling, Bluetooth audio streaming, as well as USB media device connectivity (thumb drive or iPod). It fully emulates the MBZ factory cell phone interface so all the buttons on the steering wheel and radio unit work as intended, and phone book and call info is displayed on the instrument cluster LCD panel. The media interface emulates the CD changer for USB or iPod music playback.
This works only for "facelift" vehicles with the MOST fiber optic system, so for most models, this means MY205 or later (except for the ML and G, which would be MY2006 or later, I believe). It requires the removal or disconnection of the factory CD changer, if so equipped (it does not require that you have the changer in the first place, though). It also will not work if the factory cell phone interface is installed - it would need to be removed or disconnected. But if you have that, you probably don't need this.
I was using this in my CLK550. I removed it before trading that car in for my SL. Here's a link to the manufacturer website:
mCAR Multimedia Interface - Bluetooth and iPod to Stereo with Audio Streaming
And here's the brochure, special config instructions, sample config file, and user's manual on my website:
Benzbits: mCar Interface Info
Note that mcar's compatibility guide lists "2004" vehicles. That is not correct - it's MODEL YEAR 2005 or later, as that was when the "facelift" occurred and the switch from D2B to MOST fiber. Of course some MY2005 cars were sold in calendar year 2004, so I think that's their reasoning. This ONLY works on the MOST system!
I'll also include a genuine Mercedes mic. I used the mic that came with the mcar unit, but it was not so great. I had been told that using a MBZ mic was better, so I pulled this from my C240 to try, and I'll throw it in. It will need some splicing to wire in if you choose to use it.
$400 delivered via FedEx ground/home within continental USA only. Payment via Paypal only.