 Approximately 4,500 examples were built (1,750 2003MY and 2,750 2003.5MY), thus launching the MazdaSpeed Program to a commercial success.The Callaway Project C15, was originally known as Corvette Z06.R GT3, a competition version of the Corvette C6 Z06 built to compete in FIA GT3 category GT racing.The cars are built at Callaway Competition's facility in Leingarten, Germany and raced in the FIA GT3 European Championship.