In 1969, there was a 4WD boom in F1 with the top teams of the era, with  Matra, Lotus and McLaren, building 4WD cars. Only Matra used the Ferguson system. (Cosworth also built a 4WD car but using their own system). The 1968 seasons had seen many wet races and the constructors were searching for means to increase the grip of the cars. The 1969 British Grand Prix, saw a record number of four 4WD cars entered, with John Miles in a Lotus 63 achieving the best finish of 10th.  Tyre technology had vastly improved and 1969 also saw the introduction of wings in F1 and as there was no wet race that year, all the competitors ceased developing 4WD F1 cars as wings appeared as an easier way to increase grip. 4WD no longer presented any advantage in F1, if it ever did. Team Lotus made a last attempt with the Ferguson system on the gas turbine powered Lotus 56B in 1971, but the car was uncompetitive. Eventually, in 1971, Tony Sheldon decided that too much money had been pumped into research with no real result and closed down Harry Ferguson Research Ltd