The Lancer Evolution (colloquially known as the "EVO") is Mitsubishi's flagship sports car. Based only on the unibody of the domesticated Lancer sedan, the Evo is a rally inspired, turbocharged, all wheel drive, durable, and finely tuned automobile. The number designation of the model is most commonly a roman numeral. Evolution models prior to version V were the officially approved models for Mitsubishi's efforts in the World Rally Championship's Group A class and SCCA Pro Rally Championship. In order to follow these rules, the Evolution is based on the same platform as the Lancer. However, it is much more powerful than the Lancer, with the unibody being the only major part in common between the two. Nine street versions of the Evolution have been produced from 1993 up to today. Evolution versions VI, VII, VIII and IX did not need to meet WRC homologation requirements.