who knows.. but lets use the simplest of logic here..
and by the way im not trying to offend u in any way, although it may soud like it
when the kwik sound, or whatever keeps happening, that means that something is rotating inside the car and it is hitting something, right?
this only happens when the handbrake is up, which means it has something to do with the handbrake.
the bmw handbrake is much different from most other cars, it is actually behind the rotor.
well, when u open it up you would probably see..
now, sometimes mechanics are in a hurry, and sometimes their just plain stupid.. other times their not..
some mechanics dont really analyze the problem, they just replace anything that gets into their way,
while it was under warranty, i dont know why they didnt replace the whole parking brake mechanism.. that would be smart because it only happens when the parking break is on, right? i dont know WHY they replaced the rotor..
anyway, good luck. i tink if u look at it u might be able to figure it out