 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 Brazilian Grand Prix, which Piquet won but was later disqualified for circumventing the minimum weight limit by running water-cooled brakes. Both drivers also raced the BT49 at the 