The B platform (also known as the B body) is a full-size rear-wheel drive car platform that was produced by General Motors (GM) from 1926 to 1996. Originally made for Oldsmobile and Buick, all of General Motors's five main makes would use it at some point. It was closely related to the original rear-wheel drive C and D platforms, and was used for convertibles, hardtops, coupes, sedans, and station wagons. With approximately 12,960,000 units built, divided across four marques, the 1965-70 B platform is the fourth best selling automobile platform in history after the Volkswagen Beetle, Ford Model T and the Fiat 124.