I think the rear calipers are seized on my 200. There is a grinding noise coming from them, i've removed the wheels and checked the pads and there's plenty left on them but when i turn the discs you can hear them rubbing and the disc are now scored, they also bind when i leave the car on the drive over night. I've also tried pushing the calipers back but they don't budge. Can anyone tell me if they are covered under warranty?