After completing his national service in the 1950s, Gubby became a freelance motor trader, and throughout his career he developed his business interests to include several garages and car showrooms, a hotel and a building company.

[1] Gubby started his motor sport career in rallying, and also raced a Speedwell-tuned Austin A30 and a 3.8 litre Jaguar[2] before switching to single-seaters in Formula Junior in the early 1960s.

[3] In practice, having posted the eighth fastest time and outqualifying his closest rival Peter Revson by a second,[4] Gubby's Lotus suffered a wheel failure and he crashed heavily through chainlink fencing.

[2] Gubby's single attempt to participate in a Formula One World Championship race, the 1965 British Grand Prix at Silverstone, also ended with problems in practice.

[1] Other well-known horses trained by Gubby include Easy Dollar, Omaha City and more recently Son of the Cat, which won the Stewards' Sprint Handicap at Goodwood in July 2011.