Oh no, you're probably right. I'd ignored CAN, thinking it was for internal lights and windows and such. This CAN diagram doesn't show much about headlights, amps, etc... that I can understand. I've been searching with W210 also, and should start looking with the stock headunit/amp model numbers too, perhaps.

It's odd that the wiring harness has almost enough pins to match the ISO harness and they are colored similarly. I'm going to call the stock headunit manufacturer (Becker) about the pins.

Stig, was the steering wheel adapter required to allow the empeg in your car? I see a ~$500 one for my car, which I'd like to avoid.