With the arrival of ground effect in 1978, the car became obsolete, even in its remodelled WR4 configuration, and was used only in some of the races. WR3 and later WR4 were given to Theodore Racing for their new recruit Keke Rosberg, who finished just one of his races in the car, at the 1978 German Grand Prix. Scheckter scored one more podium finish in WR1 at the 1978 Monaco Grand Prix. Halfway through the season, the WR1 design was replaced with the new Wolf WR5.