outside the UK, including 45 per cent to the US and 25 per cent to mainland European markets. The 1968 model featured dual system (aka tandem) brakes with a brake failure warning device. The engine used a revised camshaft and a distributor with idle speed ignition timing retarded to address emissions. The twin SU carburettors now included overrun valves in the throttle discs and anti-tampering features on carburettor fuel-air mixture nuts. Starting in 1969, US-bound models were "federalised" to comply with safety and emissions regulations. A reduced compression ratio of 8.5:1 resulted in a slight decrease in power (68 bhp) and 73 ft-lbs of torque. However, the 0–60 time of 14 seconds was still faster than the Mark II. The instrument panel was moved in front of the driver, and new seats were introduced with integrated headrests to help against whiplash. Cosmetically, the wood dash was replaced with a matte black finished assembly intended to imitate an aircraft cockpit. The Mk. III's final production year (1970) included an integrated rear reverse and license plate lamp, side lamps at the front and rear and new badging. The separate "Triumph" letters on the front of the bonnet were removed and "Triumph" and "Spitfire" rectangular badges were used in the front, rear sides and rear. A limited number of U.S. market 1970s were adorned with an RAF style "Spitfire" badge (U.K. models had a plain badge without the RAF roundel) that rested in the right corner (car opposing point of view) of the bonnet. Additional exterior changes introduced included a zip up rear window, black radiator grille and a black (vs body coloured) windscreen surround. Full wheel covers of two styles were used including the 1969 introduced model with "SPITFIRE" circumscribing the hub and a unique derivative without the branding. Interior changes included a steering column mounted ignition switch, a key-in-ignition warning buzzer, driver's side under-dash courtesy lamp and a new black spoked steering wheel. Under the bonnet, some markets had the twin SU carburettors replaced with a single Zenith-Stromberg carburettor. Spitfire Mark IV (1970–74) The Mark IV featured a redesigned rear, similar to the Triumph Stag and Triumph 2000 models, both also designed by Michelotti. The front end was revised with a new bonnet pressing, eliminating the weld lines on top of the wings, door handles were recessed, the convertible top received squared-off corners. The interior was revised to include a full-width