The championship was first awarded in 1991 and has been contested every season since then. The class structure is modified for 2008 as follows: Class A, for road based saloon and sports cars up to 1600cc. Class B is contested by modified, road based saloon and sports cars with engines of up to 2000cc. Class C follows the same rules as Class B, except that it requires engine sizes to be above 2000cc. Finally Class D is for cars conforming to
Touring car racing regulations and re-engined sports cars, such as
Caterhams. Points are awarded depending on where the driver finishes in their class (in essence, there are four race winners), with the overall championship being awarded to the driver who has managed to accumulate the most class points, regardless of their overall results in the races. ==Champions==