Ernie Unger worked at Lotus in 1954 and 1955 as a mechanic and racing car preparer, then entered the student-apprenticeship program with the Rootes Group, eventually becoming a development engineer on the Hillman Imp.

[4][5] Inspired by the sophisticated engineering and body development of the Italian Abarths, Unger produced sketches for a car meant to combine these qualities with the excellent vehicle dynamics of the best contemporary British sportscars.

[7] Dare-Bryan was a free-lance automotive designer who had previously worked at Lotus alongside Colin Chapman, and with aerodynamicist Frank Costin.

[6] Ron Bradshaw was working on the design of Ford's new GT40 when he was approached by Unger and Dare-Bryan about their project, and agreed to draw the new car as well.

[17] In a reference to the transverse mid-engined Lamborghini supercar that debuted one year earlier, the GT was dubbed the "Mini Miura" in the pages of Sport Auto magazine by racing driver and journalist José Rosinski.

[21][22][9][13]: 109  UWF bought the car and assembly line from UPD and restarted production in Park Royal, West London.

The UWF cars had some minor changes from the ones built by UPD, including softer springs, new alloy wheels, a revised dashboard and new taillamps.

[4][5] Other references use the MkII designation for a planned successor to the GT that would retain the mid-engine layout but be larger than the original car.

The "Mk2" moniker has also been used to refer to a much later design done by Dare-Bryan for a successor to the GT, this one powered by a mid-mounted Toyota powertrain, that never reached fruition.

[23] UWF stopped production of the Unipower GT in late 1969, and the last car was delivered in early 1970.

[25] In late 2016, four Unipower GT's, the first production Unipower GT built, the first Competition version built, a Left Hand Drive version and the last of the UPD cars produced and undergoing a major restoration, with their respective owners, Tim Carpenter, Gerry Hulford, Mark Glaisher and Thomas Jay, gathered at the Supercar Classics event at Beaulieu, England, organised by the Unipower GT Owners Club & Register, in celebration of the 50th anniversary of the car's launch.

[26][27] The Quasar Unipower city car is related to the GT only in so far as it is built by the same parent company, and is powered by an engine from the same family.

[28] The car's body was shaped like that of a rectangular prism, with the four side faces and the top made of glass.

[30] Access to the interior was gained via one of six sliding glass doors, and the car could accommodate up to six people on clear inflatable seats.

[29] Gianfranco Padoan was an amateur racing driver and owner of an Italian automobile tuning and accessories company called ESAP, an acronym for Equipaggiamenti Sportivi Auto Preparazione.

[31] In 1967 Padoan, who started racing Minis in 1964, ordered a left-hand drive Unipower GT and picked it up at the factory.

Back home in Italy, he was unable to have the car certified for road use by the Ispettorato Generale della Motorizzazione due to non-compliance with Italian requirements for the size and height of the headlamps.

Padoan modified the car's body, creating a new forward-tiling one-piece nose that had larger and higher rectangular headlamps.

Inside, the gear shift lever was moved from the sill to the centre of the cabin between the driver and passenger.

By the time he was finished, Padoan considered the result a new car, which he called the ESAP Minimach GT, and sought financing to put it into production.

[32] The car, priced at ₤1,735,000, was presented to the Italian press in February 1968 and appeared at the Geneva Motor Show in March.

Construction took place over approximately 15 years, during which time the racing class the car was intended to compete in was ended.

[4][36] The spaceframe chassis was fabricated of square and rectangular cross-section steel tubing and included integrated roll-over protection.

[39] 1266.9 was purchased by Salisbury tuning firm Janspeed and raced internationally on one occasion in Madrid for them by BMC works driver Geoff Mabbs in the latter half of 1967.

Serial number UWF1007 was a car with special lightweight carbon fibre reinforced fiberglass bodywork made by Specialised Mouldings.

Other racers were campaigned by John E. Miles (for Em Newman and Gordon Allen), Andrew Hedges, John Blanckley, Stanley Robinson, Roger Hurst, Tom Zettinger and Alberto Ruiz-Thiery who all raced cars on the continent at such venues as Mugello, the Nürburgring, Spa, Barcelona, Jyllandsring, Vila do Conde, Zolder, the Targa Florio and Jarama.

In addition to the specially prepared competition GTs, several private owners raced their road cars at various venues.