The front end was also cleaned up, with a new bonnet pressing losing the weld lines on top of the wings from the older models, and the doors were given recessed handles and squared-off glass in the top rear corner. The US specification models up to 1978 still had chrome bumpers, but on the 1979 and 1980 models these were replaced by black rubber bumpers with built-in over-riders. Some markets also got a single Zenith-Stromberg carburettor. At the rear the two separate reversing lights were replaced by a single light in a central fitting which also held the number plate lights. This gave a top speed of 92 mph (148 km/h), and would achieve 0 to 60 mph (97 km/h) in 16.4 seconds.
The Mark III was the fastest Spitfire yet, achieving 60 mph (97 km/h) in 13.4 seconds, and reaching a top speed of 95 mph (153 km/h). Average fuel consumption was improved slightly at 33mpg. This put the Spitfire head and shoulders over its competition in handling. The advantage of this is to reduce external wiring as well as to provide a constant environment for TCM operation which encourages longevity.
The remaining leafs were mounted such that they were able to pivot freely. The interior was much improved: a proper full-width dashboard was provided, putting the instruments ahead of the driver rather than over the centre console. This year also received a zip up rear window, full wheel hubcaps, black radiator grille, key-in-ignition buzzer, and a new black spoked steering wheel. Although much of the bonnet pressing was carried over, the front end looked quite different.