other requirements, such as usable space. In dedicated sports cars, a weight distribution of about 50% front and rear is frequently pursued, to optimise the vehicle's driving dynamics – a target that is typically only achievable by placing the engine somewhere between the front and rear axles. Usually, the term "mid-engine" has been primarily applied to cars having the engine located between the driver and the rear drive axles. This layout is referred to as rear mid-engine, rear-wheel drive, (or RMR) layout. The mechanical layout and packaging of an RMR car are substantially different from that of a front-engine or rear-engine car. When the engine is in front of the driver, but fully behind the front axle line, the layout is sometimes called a front mid-engine, rear-wheel-drive, or FMR layout instead of the less-specific term front-engine; and can be considered a subset of the latter. In-vehicle layout, FMR is substantially the same as FR, but handling differs as a result of the difference in weight distribution. Some vehicles could be classified as FR or FMR depending on the factory-installed engine (I4 vs I6). Historically most classical FR cars such as the Ford Models T and A would qualify as an FMR engine car. Additionally, the distinction between FR and FMR is a fluid one, depending on the degree of engine protrusion in front of the front axle line, as manufacturers mount engines as far back in the chassis as possible. Not all manufacturers use the Front-Mid designation. Examples FMR layout – Front Mid-engine / Rear-wheel drive These cars are RWD cars with the engine placed between the driver and the front axle. Alfa Romeo 8C Competizione AC Cobra Aston Martin Vantage (2005), (2018), DB9, DB11, DBS V12, DBS Superleggera BMW Z1, Z8 Chevrolet Corvette (second through seventh generations) Bill Thomas Cheetah (used only one universal joint between transmission tailshaft housing and differential housing) Dodge A100 and Viper Ferrari 599 GTB Fiorano, 612 Scaglietti, F12 Berlinetta, 812 Superfast and GTC4Lusso T Ford Econoline (first generation) Honda S2000 Jaguar E-Type Lexus LFA Maserati Quattroporte V, GranTurismo/GranCabrio Mazda Bongo (second generation), RX-7, MX-5 and RX-8 Mercedes-Benz SLR McLaren, SLS AMG and AMG GT Morgan +4, 4/4, Aero 8, Plus Four, Plus Six and Plus 8 Opel GT (original) Porsche 924, 944 and 968 Shelby Daytona Toyota Previa (first generation) and 2000GT Most pre–World War II front-engine rear-wheel-drive cars FM4 layout – Front Mid-engine