Bizzarrini P538 drivers Edgar Berney and Andre Wicky, but records indicate both retired after three hours with a cooling problem. A second team in a production-based Bizzarrini A3/C, driven by Sam Posey and Massimo Natili, was disqualified after a pit lane violation, possibly while returning with serious frame damage. American Ferrari driver Mike Gammino then commissioned a Lamborghini 4.0-liter V12 powered car, which he raced once. Bizzarrini attempted to build a second, 3.5-litre V12 car for Le Mans, but was unable to complete it before bankruptcy. Beginning in the mid-1970s and continuing at least through the 1990s, former Bizzarrini engineer Salvatore Diomante
Production car speed record speed for both runs is taken as the car's top speed. In instances where the top speed has been determined by removing the limiter, the test met these requirements, and the car is sold with the limiter on then the limited speed is accepted as meeting this requirement. For the "McLaren F1" the estimation by "Car and Driver" about the speed at the rev-limiter is used. Comparing claimed speeds of the fastest production cars in the world, especially in historical cases, is difficult as there is no standardized method for determining the top speed and no central authority to verify