Disc Brake swap-A body Rotors

"SEMA Approved" might just mean they've paid up their membership dues in full. That said, a lot of Corvette guys are running adapters now, but in their case they're deliberately trying to move the wheels out about an inch to deal with putting wheels of the wrong offset on their cars. I haven't seen one of the typical Corvette adapters but they may not be built in quite the same way.