Purchased my 550i in September. After about a month of loving the car, one day in October I was making a left turn and the engine shut off on me making the steering wheel hard to turn. Thank god it was late night and there was no traffic. The lights and radio was still working and it had me confused. This happened a few times, I would be driving and Bam! Shut off in the middle of the street. The car would also shut off at a red light, very embarrassing lol.

I finally got the integrated supply module replaced and the problem went away. I've been enjoying my 550i ever since.