Penske graduated from college in 1962, and went to work for the aluminum company Alcoa. He also abandoned his status as a semi-professional racer to turn professional. He bought a Cooper-Climax Formula One race car, which he converted into a two-seater sports car. He outfitted the car's chassis with a lightweight aluminum body, and named it the Zerex Special. He took the Special to earnings of $34,350 in 1962, which also earned him the title "Driver of the Year" in the New York Times. Penske entered the 1963 NASCAR Grand National Series in 1963, winning five races driving a Corvette Chaparral GS. In 1964, Penske set the motorsports world on fire. Competing at the Bahamas Speed Week, he drove a Corvette Grand Sport to win the Nassau Tourist Trophy. He then drove a Jim Hall Chaparral to defeat contenders Bruce McLaren, Dan Gurney, and A. J. Foyt for the Nassau Trophy. He retired from racing at this point, buying a Chevrolet dealership in Pennsylvania. He returned to racing briefly, entering the 1966 Sebring race in a Corvette Grand Sport.