Paired my iphone with my 05 e46 330xi yesterday. Worked like a charm. No real noticeable decline in battery life, although if I was using it constantly in the car, I'm sure I'd start seeing one.
Now: (Welt: 31.01.08, PCD: 28.03.08):
Montego/Saddle/Dark Burl '08 e92 6MT 335i coupe --
premium, sport, navigation, heated seats, park distance control, iPod, comfort access
Steel Blue/Grey Leather '05 e46 330xi -- premium, heated, xenon
They really do have heart and soul....