The car was built by Reg Parnell, the racing driver who would go on to earn the nickname the ‘Emperor of Goodwood’ thanks to the speed and success he had at the venue, and finished in 1939 when the threat of war meant that plans to build a one-off engine were ditched in favour of an ERA B-Type engine. In that configuration, it had one outing at Prescott before the onset of war.
Reg Parnell kept hold of the Challenger throughout the conflict, as well as a number of other racing cars. As the war drew to a close, the Challenger was ready to go again. The ERA engine had to be returned so instead a much larger straight-eight Delage unit went in its place. At the same time, the steering was moved ahead of the axle and a small trap door in the nose of the new bodywork was added, granting access to the supercharger.
Eventually the car was converted to a two-seater and fitted with a Lagonda engine, and from there it was shipped to California before disappearing entirely for several decades. There were theories that it was in the Lagonda club, and eventually ERA fan Bill Morris found it and Duncan bought it. It came as a bare chassis complete with suspension, but not much else. The two-seater body is now fitted to another chassis, while the engine, gearbox and other mechanical parts were also missing.