By the mid-1970s, most of the flamboyant British spy shows had been decommissioned in favour of grittier crime-action dramas filmed on location with live action car chases.

The Sweeney’s debut in 1975 set the standard for 'real life' action-dramas, pubs replaced casinos, gone were exaggerated karate chops and rep-mobile saloons screeched around grimy street corners.

British police departments didn’t issue Aston Martins and few blue-collar sports coupés were affordable or reliable enough to be featured regularly.

The producer and screen writer, Brian Clemens, who was behind the definitive British spy series, The Avengers , back in 1961, had just seen his 1975 re-launch end after two years.

Although The New Avengers had live action scenes to rival American imports, audiences failed to connect with the outlandish plots, but did appreciate the cars.

The deal with British Leyland to supply the cars for the series was ground-breaking, a marketing masterstroke, but reliability issues cau...