I just purchased a 2008 Pontiac Solstice GXP T2 SCCA edition. I don't know if my vehicle has had the "mod" from GM done to it or not. I'm getting 21psi of boost and I have Borla exhaust and a cold air intake. You can hear the wastegate open and let off pressure, but I don't know if that is aftermarket. I was told that everything on the vehicle is GM authorized except the wastegate. I figure if the GM "mod" was done, then I'm somewhere around 310hp..... I was just curious if there was an easy way to find out. PS - The car is an absolute ROCKET!!!!!!!!!!!!!!