[FrenchBoy]

I have warped my rotors while at the track with 325Ci in the past. It was due to the pads being too aggressive for the rotors (race type pads) and not performing a proper cool down lap. Also, it is recommended to inch the car back and forth slightly while it's parked cooling so that the hot pads don't face the same spot on the rotors for too long.

I am surprised this would happen with stock pads and rotors though.