Failure syndromes:
Intermittent simultaneous failure of wipers, sunroof, windows, central locking, radio...
No power, like if the battery was dead.

Sometimes even everything works fine, then the car does not start anymore for hours or days. Reason are haircracks. I helped out someone here in Japan who even wanted to scrap the car due to this intermittent failures.
And note! There are 2 !!!! fusible links under the rear seat.

http://www.bimmerboard.com/forums/posts/377728