On the other end of the spectrum lies the 2011 Chevrolet Corvette Z06X Track Car Concept, which takes a standard Z06 and stuffs it with an SCCA-approved roll cage, racing seat and harness and fire suppression system. Besides the required racing bits, the car has been extensively lightened thanks to carbon fiber body panels, a polycarbonate rear window and the removal of the radio, carpets and sound-deadening material. Again, just a concept, but if there was ever a 'Vette to put up against the Dodge Viper ACR-X, this is it.