Since last 3 weeks, rear brakes are squeaking any time I brake in any condition. Cold, warm, wet, dry, slow driving but not fast driving. This happens only when I apply the brakes. I was reading and many owner has squeaky brakes. I wonder is it under warranty or abnormal wear or anything else. The car has around 12000 miles on the clock... I checked the rotors and front ones has more wear than rears. I didn't notice any scratches or discolouring or rust. I was having squeaky brakes before intermittently but now it is getting louder and every time when I apply the brakes I can hear them squeaking. Any suggestions?