He was also well known in motoring circles for his successful car dealership, Marshall Wingfield, originally located on the Finchley Road, London, before moving to Brook Street in Tring and through his adult life lived in Harrow, Chiswell Green, Bricket Wood, Hemel Hempstead, Northchurch, Aston Clinton and Pitstone.
He also won the 1971 Escort Mexico championship, beating future Formula 1 World Champion Jody Scheckter and finished 2nd in the 1974 Avon Tour of Britain driving for the same team as the equally respected rally driver Roger Clark.
Although he rolled the car at Mallory Park in practice he was able to keep racing until money and impending engagement (to Carol) forced the sale of the Mini and absence from the tracks for a few months.
Driving Newtune's 1275s in the Snetterton 500 km with David Warnsborough the pair won the 1300 cc class in the European Saloon Car Championship race.
"The meeting Gerry Marshall will want to forget" was the headline Auto News gave for a Brands Hatch sprint in the July.
On a wet track Marshall had aquaplaned off the circuit at Paddock Hill Bend and pretty much wrote off the Barnet Motor Company's Elan, which had only been raced a handful of times.
As reported in Sporting Motorist "Gerry Marshall really gets to grips with his motor cars and flings them about with such gay abandon that people expect him to fly off the road – he has been named the Jochen Rindt of club racing, also the Mr. Dunlop Benefit (by commentator Barry Simons) but he rarely does and more often than not wins".
Marshall raced Lotus Elans, the special Costin Amigo, Ford Escorts (winning the inaugural Mexico Championship from Jody Scheckter in 1971 and also finishing runner up to Roger Clark in the 1974 Avon Tour of Britain), Lola T70, Holden Torana at Bathurst, Hillman Avenger, Clan Crusader, Austin Marina, Birdcage Maserati, Mk2 Jaguar, Sunbeam Tiger Le Mans, Porsche 924, an Alfa Romeo, Chevrolet Camaro and BMWs.
When in 1977 DTV and Vauxhall decided to go rallying everyone thought Marshall would be okay and there were rumours flying around of offers and deals involving Ford and Leyland products.
The Capri driving was not the success that Marshall had hope, with the Tricentrol Championship costing more than anticipated and the only result of note was the start of the season, in the wet at the International Trophy at Silverstone, when he finished first in class and second overall.
There was also the accolade of John Webb and the BARC organising the Gerry Marshall Benefit Races at Brands Hatch and sharing the Dolomite with Roger Clark at the TT event at Silverstone and all seemed to be going well with Marshall really being at the height of his career when disaster struck at the Grand Prix support race in July 1979 which was supposed to be the highlight of the year, with good rides in the Dolomite and Lister Jaguar.
Almost flat out down the straight from Stowe to Club, Marshall was fractionally ahead of Walkinshaw's Mazda and keen to stop him moving up to challenge class leader Greenslade.
A few feet before the 100yds marker board, the two cars touched and Marshall was launched into a series of rolls, the severely damaged Sprint landing in the catch fencing at Club" Autosport, 19 July 1979.
During the accident, the sheer force made his helmet come off (still intact and fastened) and the mountings of his seat had broken, which meant he was thrown around the inside of the car, unprotected.
For the 1980s Marshall decided to retire from full-time Group One racing as he wasn't happy with the current regulations and there was a disagreement with British Leyland.
More racing (and winning) followed in the 1990s, notably in the TVR Tuscans (narrowly missing the title in 1991 due to political moves) and also the famous Marsh Plant Aston Martins.
In 2000, on 6 August he scored his 600th win at Snetterton in the Marsh Plant Aston Martin DB4 and also made a return to racing a Vauxhall Firenza, driving one of the original 1974 Thruxton racecar Droop Snoots.