The American touring car series, officially called the Trans American Sedan Series, started out based on FIA group 2. But the rules were often changed after 1972, ending with very liberal spaceframe cars. It started as a makes championship.
|FIA group 2 years||1966 1967 1968 1969 1970 1971 1972|
|1973 and further||take a look at World Sports Racing Prototypes|