I'm going to add some more information here.
I just had all 4 rotors replaced, so those are brand new. All rotors but this one (pass. rear) all wear fine. They are all worn after a quick drive. I also hear some clunking "clunk clunk clunk clunk" while applying the bakes hard. If I lightly apply the brakes, there is no clunk, but when pressing harder, it is deffinatly there.
hopefully someone can help me out