We bought a '12 Mustang GT premium, Brembo pkg w/ 3.73 in July and it has been in the shop 6 times and about to go back. The most recent problems are rear brake squeal, of which it has been in 4 times and about to go back again. But the major problem this past visit was rear end whine. They replaced the ring and pinion, which seemed to correct the problem until we heard it again on a Sunday cruise. We left to go to dinner this evening and heard a loud noise from the rear, unlike anything we have heard before. Sounds like both axles are about to leave the car, and we never got above 20mph. I'm calling the dealer in the morning to come and pick it up. At this point, I'm not sure I want it back.