Does anyone have a wiring schematic for the stereo on an '87 325is? The PO of my new toy installed his own and I want to find out what (if any) of the old system I can use. The "is" model has tweeters in the doors just inside the mirrors. I have a decent Kenwood unit, but there is no low end and weak high end, I want to make sure it is done right before I just start ripping.