Thanks for the wiring diagram. I had already gone down that path since I have the CDs and WIS, but could not identify the specific connector.
The radio in the car is the original one according to the Becker website: http://www.beckerautosound.com/1492-1994-95/index.html
It shows only the 3 connectors which I've already connected. It's just the wire with the clip that I'm trying to figure out. It's a single wire (oragany-red with a blue stripe) that ends in a male connector which is attached to a metal clip about 1.5 inches long. It may not even belong to the radio as there certainly isn't a spot in which to insert it.
Bob