My rear groan (
) has come back after all of my ranting and raving in the beginning. But, I'm carefully to come to a rolling stop now instead of the usual stop all other vehicles can make. If I have to stop quickly, the groan is there. Otherwise, it's minimal. Another dealer took care of the problem (after months of complaining and an ongoing dialogue with GM) by resurfacing the rear rotors and 'camfering' <spelling?> the brake pads. Good luck and let us know what you find out!