 Complete the following phrase:  Team Penske used the PC3 for the first six races of the season, but for the Swedish Grand Prix the PC4 was introduced. The teams sole driver, John Watson, qualified the new car 17th on the grid but crashed on the first lap of the race when its throttle became stuck. Following aerodynamic revisions and a lengthening of the wheel base, the PC4 proved to be quite competitive. Watson fared much better at the following 