Another historical case, Smokey Yunick, the car racer and mechanic:
As with most successful racers, Yunick was a master of the grey area straddling the rules. Perhaps his most famous exploit was his #13 1966 Chevrolet Chevelle, driven by Curtis Turner. The car was so much faster than the competition during testing that they were certain that cheating was involved; some sort of aerodynamic enhancement was strongly suspected, but the car’s profile seemed to be entirely stock, as the rules required. It was eventually discovered that Yunick had lowered and modified the roof and windows and raised the floor (to lower the body) of the production car. Since then, NASCAR required each race car’s roof, hood, and trunk to fit templates representing the production car’s exact profile.
Another Yunick improvisation was getting around the regulations specifying a maximum size for the fuel tank, by using 11-foot (3 meter) coils of 2-inch (5-centimeter) diameter tubing for the fuel line to add about 5 gallons (19 liters) to the car’s fuel capacity. Once, NASCAR officials came up with a list of nine items for Yunick to fix before the car would be allowed on the track. The suspicious NASCAR officials had removed the tank for inspection. Yunick started the car with no gas tank and said “Better make it ten,” and drove it back to the pits. He used a basketball in the fuel tank which could be inflated when the car’s fuel capacity was checked and deflated for the race.
Another historical case, Smokey Yunick, the car racer and mechanic: