GT3 and below cars with a mixture of professional and pro-am drivers. Production-car racing Production-car racing, otherwise known as "showroom stock" in the US, is an economical and rules-restricted version of touring-car racing, mainly used to restrict costs. Numerous production racing categories are based on particular makes of cars. Most series, with a few exceptions, follow the Group N regulation. There are several different series that are run all over the world, most notably, Japan's Super Taikyu and IMSA's Firehawk Series, which ran in the 1980s and 1990s all over the United States. Stock car racing In North America, stock car racing is the most popular form of auto racing. Primarily raced on oval tracks, stock cars vaguely resemble production cars, but are in fact purpose-built racing machines that are built to tight specifications and, together with touring cars, also called Silhouette racing cars. The largest stock car racing governing body is NASCAR (National Association for Stock Car Auto Racing). NASCAR's premier series is the NASCAR Cup Series, its most famous races being the Daytona 500, the Southern 500, the Coca-Cola 600, and the Brickyard 400. NASCAR also runs several feeder series, including the Xfinity Series and Gander RV & Outdoors Truck Series (a pickup truck racing series). The series conduct races across the entire continental United States. The NASCAR Pinty's Series conducts races across Canada and the NASCAR PEAK Mexico Series conducts races across Mexico. NASCAR also governs several smaller regional series, such as the Whelen Modified Tour. Modified cars are best described as open-wheel cars. Modified cars have no parts related to the stock vehicle for which they are named after. A number of modified cars display a "manufacturer's" logo and "vehicle name", yet use components produced by another automobile manufacturer. There are also other stock car governing bodies, most notably the Automobile Racing Club of America (ARCA). In the UK, British Stock car racing is also referred to as "Short Circuit Racing". UK Stock car racing started in the 1950s and grew rapidly through the 1960s and 1970s. Events take place on shale or tarmac tracks – usually around 1/4 mile long. There are around 35 tracks in the UK and upwards of 7000 active drivers. The sport is split into three basic divisions – distinguished by the rules regarding car contact during racing. The most famous championship are the BriSCA F1 Stock Cars. Full-contact formulas include