I wouldn't worry about it mate. You get the extended warranty, if something wasn't done right it would show symptoms. Mine was recalled by BMW Australia, so I was told by the dealer, and it absolutely screams....watch my exhaust video, there's nothing wrong with that motor
EDIT: have done 7000 kms since the recall, hasn't missed a beat and I'm not easy on it either
Dude nice video but I see a couple thing wrong. 1st. Your on the wrong Sind of the road! 2nd, Oh man can the 5-0 hear you coming from a long way off!
No really nice sound made me feel I was at the track.
Thanks ; )