• Episode 4 - Chevrolet Corvette ZR1 vs C6.R Road & Track Presents -- Its a battle of American muscle when the Chevy Corvette ZR1 battles it out on the track against the explosively quick C6.R in part 4 of The Ultimate GT Showdown. Hosted by IndyCar driver and commentator Sam Posey, and includes on-track driving by Jan Magnussen.