basically the international race of champions they take the top performers from a bunch of classes, nascar, busch, and Indy as well as some others and give them cars that have been tuned as close to one another as possible. The people race these cars once a year and prove who is the true best racer.

at least one year it was the camaro, and i think it usuall (always?) is? Chevrolet than sells a similarily tuned car on the open market.