At that time, the original flat-fronted Firenza model was rebadged as the Magnum coupé, and the name Firenza was used exclusively for the HP version. This car was an exciting styling departure for Vauxhall, and certainly created something of a buzz. The engine was the 2.3-litre variant of the OHC Slant Four engine, uprated to a very torquey using a variety of parts developed by Blydenstein Racing. It had twin 175 Stromberg carburettors, high-lift camshaft and free-flow tubular exhaust manifold. The car was restyled on the David Jones original by American designer Wayne Cherry and the result was an exceptionally low drag coefficient for its time. Suspension was uprated and lowered, brakes uprated, and a 5-speed ZF dog leg gearbox was installed, a much stronger unit than fitted to the standard model (though rather noisy). Another unusual feature of the car was the alloy Avon Safety Wheels, which were designed to retain the tyre safely in the event of a puncture. This was the first car to use these wheels in production. All production cars were painted in the same colour - Silver Starfire, and featured a largely black interior with silver-grey cloth seats. An unusual interior feature of dubious utility was the passenger grab handle on the dash in place of the standard glovebox.
