found in North American cars. Better interior ventilation was provided via flow-thru vents in the rear pillars in addition to a two-speed blower. Interior window cranks and door levers were changed and shared with the TR6 model. Tops of interior doors were covered with foam backed vinyl trim. US Market cars also received high back reclining bucket seats. The rear backup/license plate lamp fixture for 1970 was borrowed from the e-Type Jaguar, further cementing the e-Type associations. No doubt a consideration by Triumph to play it up. "The 'plus' is easily identified by the newly designed enamelled badges asymmetrically placed at the rear and on the hood." Rear tinted glass with integrated heating element was also equipped. Optional extras available for 1970 included safety hex-hub, centre locking, 60 spoke double laced wire wheels with each spoke "hand torqued to Triumph specifications". Racing mag or aluminium wheels, custom chrome plated steel roof rack, bumper guards, space for under dash radio were also listed. GT6 Mk III The final major facelift for the GT6 came in 1970 in the form of the Mk III. This time the entire bodyshell was revised to match the changes made to the Spitfire Mk IV: modifications included a cut-off rear end, recessed door handles and a smoother front end. Only detail changes were made to the mechanics, but in 1973 – close to the end of the car's production life – the rear suspension was changed again, this time for the cheaper (but still effective) "swing-spring" layout fitted to the Spitfire Mk IV. This was a modification of the swing axle rear suspension used on the Herald-derived models, with the transverse leaf spring mounted on a pivot, eliminating roll stiffness at the rear, and thus greatly reducing the jacking effect under cornering loads. To compensate for this loss of roll stiffness, a larger front anti-roll bar was fitted. A brake servo was also added in 1973, and seats were changed from vinyl to cloth. There was still a fairly comprehensive options list, but the knock-on wire wheels were no longer available. The unladen weight increased slightly to . Engine power and torque for the Mk III was similar to the Mk II, but better aerodynamics led to a new top speed of and a time of 10.1 seconds. Performance was now comfortably ahead of the MGB GT, which reached about and in approximately 13 seconds. Fuel