The Lotus 23 was designed by Colin Chapman as a small-displacement sports racing car. Nominally a two-seater, it was purpose-built for FIA Group 4 racing in 1962–1963. Unlike its predecessors Lotus 15 and 17, the engine was mounted amidship behind the driver in the similar configuration developed on Lotus 19. The 23 To comply with FIA rules, it had a regulation trunk space to the right-rear of the driver, a windshield wiper, a horn, pairs of headlights and tail lights, rear center license plate light, a wire-operated emergency brake, and a mounting space for one spare tire under the front body. The 23 used a wider version of the Lotus 22 space frame, clothed in a fibreglass body. It was originally intended for engines of 750 cc to 1300 cc (45-80ci) with a Renault 4-speed transaxle, but had a 5-speed Hewland Mk.III in production, which used the entire Volkswagen magnesium alloy transaxle case in upside-down configuration, housing bespoke straight-cut gears with dog-rings, and the Volkswagen differential gear set. Unlike the later Mk.IV/V, the Mk.III had the shifter rod at the end of the VW nose casing, so the shifting rod (pipe) from the centre shifter knob location extended to the tail end of the chassis. As this part was not completely covered by the bodywork, a following driver with good eyesight could tell when the 23 with Hewland Mk.III shifted gears. The front suspension was a typical double wishbone arms with outboard coil/damper unit using the Triumph upright made by Alford & Alder, Triumph Herald rack and pinion steering, and outboard Girling non-ventilated disc brake. The rear had the top link with lower reversed wishbone, top and bottom radius arms with the top arm at the height of the halfshaft, combined with the outboard disc brakes and coil/damper unit. Unlike the arrangement for Lotus 20 suspension, the halfshafts had Metalastic rubber 'doughnuts' on the inside, carrying no cornering (side) forces. The side forces are carried by the lower wishbone, together with the top 'I' arm link, which connects the tail end of the upper side tube in the frame with the extended top end of cast alloy upright. The tie-rod end, front top and bottom wishbone outside joints were ball joints, and the rear lower wishbone inside joints were Rose joint. The rest of the suspension joints were rubber joint, with joint-mounting pipes welded onto the ends of suspension arms.