Folks,
If you have a 94 to 97 Mercedes, your stock radio harness should look like this:
http://www.beckerautosound.com/1492.html
Do not cut this or let anyone cut this if you are replacing the stereo. Call Becker parts dept. at 888 423 3537 x1209 and ask for the "M-Class adapter". It should be item number
"5000.453-276". Should be around $19.55.
This adapter has 2 ends, one that connects to your car's harness and the other end connects to your radio. Of course, as this is made for the M-class, the the wires are not exactly straight through. Anyway, you can cut this harness in half (using the end that goes to your car harness) and make a custom adapter for any radio you'd like. I bought 2 and plan to use one to make a DIN-ISO ---> Alpine connector.
Willy