Lame, sorry to hear that... can't remember the last time I had an absolutely painless and positive service experience. Sometimes it's just the little things, like discovering that your seat is all out of whack and the memory's been erased -- but this just flat-out sucks.
At least you get a loaner. I strongly suggest that you take out your aggression on those twin turbos lurking in the 335's bonnet. It's no M3, but that engine definitely holds its own.