The Chevrolet Monte Carlo is an American mid-size car. Originally introduced by Chevrolet for the 1970 model year (as competition with the Ford Thunderbird), it has gone through six generations to date. All Monte Carlos to date have been two-door coupes, closely based on a contemporary mid-sized sedan. From its inception, the Monte Carlo also has been one of GM's biggest successes on the NASCAR stock car racing circuit. However, in 2007, GM will phase the Monte Carlo out in favor of the Impala.