A T-top is an automotive design that incorporates two removable panels into the roof of a car. When these panels are removed, they leave a center bar that stretches across the cabin of the car, connecting the middle of the front windshield with the middle of the rear. This bar gives the vehicle a characteristic T-shaped structure. The term can refer to both the roof design as well as the car as a whole.
As an alternative to a convertible, a T-top provides additional support where its needed the most, above the passengers' heads. While the two panels are removable, the center beam is permanently fixed and built into the car's structure. Automobiles with a similar design, only without this center bar, have only one removable panel leaving the area above the cabin completely open. These are referred to as targa tops.
The removable panels are usually made of safety glass approved for automotive use. In the event of a crash, the panels will not shatter the way normal glass will. Since the panels are glass, the area they occupy is transparent when they are attached.
In the late 1940s and early 1950s, the idea of a car with this design was first introduced. The TASCO was a concept car, designed after World War II, that was supposed to revolutionize the American sports car. The TASCO prototype failed, but it was the world's first T-top. Gordon Buerhig, a designer who worked on the prototype, patented the T-top in 1951.
In 1968 Chevrolet released a new Corvette model. One of its distinct characteristics was a T-top model, making it the first car in regular production within the United States to showcase this design. Though the T-top Corvettes were discontinued after 1982, the style persisted as a defining feature of other notable General Motors (GM) sports cars, such as the Chevrolet Camaro, and the Pontiac Firebird Trans Am.
One Trans Am that contributed to the popularity of the design in the US was the performance model of the Firebird production line from GM's Pontiac label. The 1977 Trans Am featured in the movie Smokey & the Bandit caused sales to increase substantially.
The following year saw GM's other budget friendly sports car, the Chevrolet Camaro, offer a T-top option, as did numerous other Pontiac models, like the smaller Fiero and the slightly less sporty Grand Prix. The popularity of the design was not lost on foreign automotive manufacturers either, with the Japanese-based Datsun and Suzuki offering T-top models as well. The Datsun 280ZX, a small, lightweight sports car, capitalized on the design, and all of the following Z models through the 300ZX would share this feature.
Other similar design elements exist. The targa top is a single, removable panel, seldom made of glass, that leaves the front and rear windshield unaltered. A cabrio coach is any car with a roof that can be moved forward and backward on a track that is located along the frame of the car at the tops of the doors. It can be positioned fully up or down.