I've got an early 6spd manual 2004 530 with 14000 miles. The only problem I have encountered is a strange "waver" in the power curve between 4000 and 5000 rpm. Had it into the dealer several times: replaced all six coils and ignition, reloaded / updated SW several times, etc. Still not fixed. Took the service manager out for a ride two weeks back -- he says it is the transition between long and short air intakes, and this was a problem on manual trans 330s a while back. He's checking to find the fix.

Anybody else have this problem / know about the fix?