The US FDA’s proposed rule on laboratory-developed tests: Impacts on clinical laboratory testing

A T-top (UK: T-bar) is an automobile roof with a removable panel on each side of a rigid bar running from the center of one structural bar between pillars to the center of the next structural bar. The panels of a traditional T-top are usually made of auto grade safety glass (tempered or laminated), or acrylic – but they can also be black or body-colored and made of other (often light-weight) materials.

The removable panel roof was patented by Gordon Buehrig on June 5, 1951.^[1] It was first used in a 1948 prototype by The American Sportscar Company or “Tasco.”^[2]

The 1968 Chevrolet Corvette coupe was the first U.S.-built production automobile to feature a T-top roof.^[3] This increased the popularity of the coupe, such that it outsold the convertible and later led to the discontinuation of the Corvette convertible after 1975 until it was revived in 1986.^{[citation needed]} Post-C3 models were built with a targa top instead of a T-top.

• Jeep Wranglers including 'JK' and 'JL' offer removable roof-panel designs that build upon the T-top construction concept
• Suzuki Cappuccino - has an optional solid roof which can be converted into a T-top
• Triumph Stag - has the underlying T-Top structure, but has a one piece, non-glass, roof panel which passes over the central front-to-back bar when in place

• Cabrio coach
• Sunroof
• Targa top