By the start of World War II, Gordon Buehrig had established himself as one of the great American automotive designers, giving style to Duesenberg and Auburn among many others. After the war, Buehrig went freelancing, and joined a start-up that wanted to build an American answer to Jaguar and other small British sports cars. The American Sports Car Company prototype Buehrig designed was inspired by aircraft — but was ungainly enough that it couldn't find a builder or backers. When the company collapsed, Buehrig took his final payments in intellectual property — spending his own money to patent on of his better ideas, a set of removable roof panels that gave passengers open-air driving.
While Buehrig got his patent for the T-top on this date in 1951, it wouldn't appear in production until 1968, when GM made the "convertible coupe" standard in the third-generation Corvette — and from there, spread throughout the industry in the '70s and '80s.