In 1959 Phil Hill set the record for the fastest MG at 254.91 mph in MG EX 181. To coincide with the 50th Speed Week at Bonneville in 1998, MG set a goal to break that record and designed EX 255, a streamliner based on the MGF shape, built on a steel tube spaceframe.

Using standard MGF doors and front wings, other panels are made from carbon fibre. The Janspeed engine based on the Rover V8, is mounted behind the driver. EX 255 rolls on high speed tyres, and is stopped by uprated disc brakes and two parachutes. Thrust SSC's driver Andy Green was selected for the attempt.

Clutch problems meant the team ran out of time and EX181's 1959 record remained.