Bought my 2008 GXP used from a MA dealer who bought it at rental auction at 12k miles in June '08 (was a former Alamo rental).
Excellent car, but burned through brakes like crazy.
After replacing front brakes with rotors at about 18k,
needed all brakes/rotors again at 25k.
Some light arm twisting at the local dealer and GM rep agreed to a whole new set of rotors/pads front and back.
Still holding at 37k though there's a lot of brake dust on the front wheels.
Smoking, fast car.
Even better than the 2000 Grand Prix GTP turbo I drove for 8 years prior.
Too bad, it's the end of an era.