Originally Posted by CyberGreg

SeaXfire, I searched for some other Mercedes radio manuals to see if I could find a difference in the wiring diagram or perhaps in operation of the radio. I was not able to locate any other Mercedes radio manuals, sorry.

I really can't imagine why it wouldn't work, here's all it has to do:
1. Convert the head phone jack into the speaker inputs on the head unit connector
2. Switch on the amp when you turn off the head unit
3. Switch on or activate when the amp signal looses power (radio off).

I'll think about it some more and perhaps others have some ideas.