It was introduced into the UK market in 1966 and continued in production until 1968, when Broadspeed's factory in Birmingham was scheduled for demolition to make way for a new ring road.

The conversion was achieved by cutting off the rear section of a standard Mini and reducing the door pillars in height by about 2 inches (5.1 cm).

Then a fibreglass fastback was bonded to the car in place of the missing rear section, adding about 4 inches (10 cm) to its overall length, and the engine tuned.

The boot was significantly smaller than that of the standard Mini owing to the presence of two fuel tanks, giving the car a range of 300 miles (480 km).

[3][a] A road test of the 1275 cc Broadspeed GT published in Motorsport magazine in 1966 reported a top speed of 112 mph (180 km/h) and a fuel consumption of 27.9 mpg‑imp (10.1 L/100 km; 23.2 mpg‑US).