One thing you'll learn is these 335i guys love going on and on about how inadequate the car is for the track. KillerFish's post above details whats needed to have trouble-free tracking time... and it's not a small or especially cheap list.
But do the required cooling mods and an LSD and the car is fine. Have fun with it.
GROUND CONTROL | STOPTECH | VRSF | COBB AP | STETT | OS GIKEN
2008 E92 335i MT