The Sports Car Club of America's SPEED World Challenge Touring Car and GT championships are dominant in North America while the venerable British Touring Car Championship continues in the United Kingdom. America's historic Trans-Am Series is undergoing a period of transition, but is still the longest-running road racing series in the U.S. The National Auto Sport Association also provides a venue for amateurs to compete in home-built factory derived vehicles on various local circuits.
Production car racing or known in the US as showroom stock, is an economical and rules restricted version of touring car racing, mainly to restrict costs.
