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