Last month I bought a 2014 Sonata with 96K miles. I noticed the brakes were making a rather loud grinding sound when I let up off the pedal. My dealership said this was normal and that they looked at the brakes and they were ok. Firestone looked at the brakes and said they were down to 1s and 2s and that one of the rear rotors was damaged heavily with a crack going almost all the way around one of the rear rotors. My dealership say that the rotor was damaged when Firestone pulled it off. They said that the lack of rust in the chip and cracks(confirmed, I have the rotor) demonstrated that the damage had not been present when the car was on the road as rust builds up almost overnight. Who is telling the truth?