 Complete the following phrase:  Brian McGuire first started to race in the British-based Shellsport G8 International Series in 1976, as a private entry with the Formula One-specification Williams FW04. He also entered the car for the 1976 British Grand Prix but was only listed as a reserve and never made it on to the track. For the 1977 season McGuire made extensive modifications to the Williams and it was entered for the 