So ive done some digging around replacing (aftermarket) head units for my clk. I currently have the single din with cassette player: https://www.ebay.com/itm/386252626785 and i wanted to change it to a double din and eliminate the need for the glovebox CD changer. Partiality because im having issue with the fiber cable for it, the plastic on it is disintegrating and because i just dislike single din radios aesthetically. Sue me!

I dont plan on changing it to any type of aftermarket unit i understand those can be a hassle depending on which audio package the vehicle came with. No rather id like to upgrade it to the facelifted double din: https://www.ebay.com/itm/196417267589 the connection on the rear looks identical but just because it plugs in doesn't mean it'll just work.

So i want to ask is it as simple as plug and play with these units or do they have to be coded to the vehicle or anything that requires programming it? And is it even compatible with the older models?


I think you are out of luck. Pretty sure they switched to MOST in 2005 and you are on previous system, D2B.

Could find a 2004 Command system, though the nav would be pretty useless.

Did some digging after reading this and you are correct MB did switch to the MOST protocal whatever it is in mid to late 2004 which is past the cut off for my CLK. Which sucks,but it taught me something new, and ill probably pivot to what you mentioned and nabbing the command unit from my years or prior and just going that route.

Appreciate you solving this for me!

It is possible to switch out the unit to an aftermarket if you have the D2B, I did this on my CLK with factory bose. A few things which im unsure on your car:

Do you have factory bose?

If not and you only have the cd changer on the fibre loop, You may actually have a more conventional stereo powering the speakers without the amplifier in the boot. If thats the case and you do have the speaker wiring behind the dash its a fairly simple switch over with an aftermarket ISO/DIN adapter which will use the aftermarket stereo to power you speakers.

If you do have bose there are two options, use a D2B converter (These are unreliable as they are mostly sellers from overseas with very little support), Open 2, send speaker cabling down to your boot to tap into the existing speaker lines from the factory amp (Essentially bypassing the amp and using your stereo to power the speakers). This method does have a massive reduction in speaker output as they are no longer amped and the bose speakers run at 2ohm so are quite demanding.

The only ones that are like for like that support full MBUX are the Chinese ones from Ali Express. You will still need a Mercedes Benz specific harness adapter.