 Complete the following phrase:  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 