Chevrolet has taken the wraps off its latest NASCAR racer, replacing the Impala that has served as the Bowtie brand's oval-racing contender since 2007 with a new shape. But there's more to the new Chevy SS stock car than just racing. The NASCAR-spec SS previews a new performance flagship for Chevrolet that will debut in February as the first new rear-drive Chevy sedan in 17 years. The new SS will serve as something of a halo model for the brand, debuting simultaneously alongside the new Holden Commodore in Australia.