In monocoque or unit construction it is integral with the body. Used when changing gear ratios during acceleration. Can connect or disconnect the engine and the drive train at driver's will. The space remaining at the top of the cylinder when the piston is at the top dead center position. Where the fuel-air mixture begins to burn.
Compression makes combustion more effective and increases engine efficiency.
Any car with a folding roof. Term used in U.S. since the 1930s. Also called a drophead coup . The conventional body has 4 doors and a folding top with roll-up windows. Usually a sporty type.