I am looking to replace my broken tape deck in my 92 300E with a Blaupunkt Key West CD player. Here is the link to the one I am looking at: http://www.crutchfield.com/S-dymB9R222Yy/cgi-bin/ProdView.asp?g=300&I=023KEYW36
1) The instructions on the website say for my car: Bypass your factory amp by running new speaker wires from the stereo to the output side of your factory amp.
2) You will need to route an antenna extension cable from the receiver to the right rear of the vehicle and connect it to the factory antenna.

Has anyone done this kind of rewiring of the factory amp as the website describes? From what they say it sounds pretty easy, but I have been told by several people that it is a royal pain to rewire the W124 for a new deck. I have previously routed wiring for a sub in the trunk, so I have some experience with the wiring of this car, but the idea of rewiring part of the car for the new deck scares me a little.
What is your take on this?

Thanks,
Leo

just wire it to the factory speaker and keep the facotry amplifier and speakers
soundgate makes a low lever interface for factory amplifier you can use that
www.soundgate.com