The one in the wagon is E32/E34 style and is PnP with a wire that is already buried behind the sunroof motor. The plug ends are yellow, and depending on build date and model, may be in your car. Since you have a 92 535, I would assumed it's hiding in there.
The E38 one is more modern looking and requires a bit of wiring up to get power to the mirror. I have the wiring diagram at home.
Which style mirror did you get, as there are a few?
Originally Posted by mholbrook