Rear brakes making a loud grinding sound while slowing a normal braking. Took to dealer 1st time could not find problem Mind you I'm a girl so they told me I was hearing things. so about A week later my boyfriend was driving the car and now along with the grinding it starts shaking when you put the brakes on so he takes it in to the shop (Carmax same dealer as before and where it was purchased) and they said it needed rear brakes it would take a few days well ok we had his car to use and after about 2 weeks we go into pick it up they said the brakes are on back order mind you the car is only 3 months old at the time it would be over a month before they get some in, so my boyfriend said well they put aftermarket brakes on it and they said nissan ok'ed it when we asked about the drums if the was replaced the said no they just turned them well we couldnt do anything about that. we ask what caused it they said me (Now till this point my boyfriend had not told them he was a Mechanic also) they said it was me I must have drove with the ebrake on but I never use it. the car's an Automatic I dont need to my boyfriend show them that he is a mechanic and that something had to cause this they said it was fine to drive and we took the car drove about a mile and it started again buy this time we were pissed and took back and called my father my cosigner it took him and my boyfriend almost getting arrested to get it fixed so we thought and at about 25k I have to pay over 650.00 to get the brakes fixed again becuase they didnt check what the problem was but Pepboys found that it had a bad brake valve switch wasnt letting the rear breaks disengage DONT BUY NISSAN SENTRAS spend 2k more and get a honda civic