 Complete the following phrase:  Brabham began the 1982 season with two BMW-powered BT50 chassis at the South African Grand Prix, where Piquet and Patrese qualified second and fourth respectively, but retired early in the race. Team principal Bernie Ecclestone was under pressure from the teams title sponsor, Parmalat, to defend Piquets championship, and opted to race with the Cosworth-powered BT49 chassis at the 