Industrialist Powel Crosley was the first to build a production model sports car in the U.S. Crosley's first car, a two-door convertible, was shown at the Indianapolis Speedway in May 1939. Crosley introduced innovations to the American automobile industry that include the use of the term 'Sport Utility' in 1948; the first mass-market single overhead camshaft engine in 1946; the slab-sided postwar car in 1946; the all steel-bodied wagon in 1947; the first American car to be fitted with 4-wheel disc brakes in 1949; and the first American sports car, the Hotshot in 1949.