By the early 1960s Rolt and FF Developments had decided that it would build a 4WD racing car to demonstrate the value of four-wheel drive technology. Rolt helped to design, and also tested the Ferguson P99. Although Rolt was more than capable of driving the car fast enough for test purposes, Jack Fairman was called in to race it in the 1961 British Empire Trophy and 1961 RAC British Grand Prix at Aintree, proving without doubt the four-wheel drive allied to the Dunlop Maxaret braking system was substantially superior in the wet. The P99 was run under the banner of Rob Walker Racing and became the only 4WD car to win a Formula One race, when in the hands of Stirling Moss it won the 1961 Oulton Park Gold Cup. The car was also the last front-engined car ever to win a F1 race. Despite a trip the Tasman Series and success in the hands Peter Westbury, when he won the British Hill Climb Championship in 1964, the car was not used much again. Subsequently the four-wheel-drive concept succeeded in the United States and in 1966 was built into the Jensen FF road car.