We bought the GXP the end of March. We had our eyes on them for a while and were very impressed with them so we crashed and burned and bought one. It's a M6 with a sunroof, with the LS3 engine. It's rated around 415hp at the flywheel and same for the torque. She's a fun car to drive and just wants to keep pulling through all of the gears! Here are some pictures.
Well we took the car to the dyno today for a charity event and she put down 352/361 untuned. The factory tune looks like CRAP on the computer. Got a lot of cleaning up to do and unfortunatly they have tuned these cars to run on regular gas. I know why but detuned the car along the way. Should get her tuned in a few weeks. I'll post numbers as we get them.