Continuity mistake: The cars change shape frequently during the movie. That depends on the fact that many scenes were filmed at real races, with real F-1 cars. The cars that the actors drove were, for the most part, disguised F-3 racers. There are at least three fake Ferraris, and they all look different. One of them seems to have been built to resemble a 1965 F-1, but altered to look like a 1966 model. The non-existent Yamura (built to resemble a Maclaren), that James Garner drives is actually two cars with different chassis, one of them seems to be used very little, except when it catches fire in a scene.
Continuity mistake: After Jean Pierre crashes he is helped out of his car. He pulls his goggles part way down as they are now just under his lip and covering his chin. The view then cuts to a closeup of Jean Pierre's face and the goggles are not over his face anymore.
Continuity mistake: During the Belgium race it begins to rain. This is making it difficult for the drivers to see. The track announcer then states about Jean Pierre," He's only 2 laps away from his third consecutive win". At this point the view changes to a frontal shot of Jean Pierre coming over a rise and look, the track is completely dry, there is even sunshine. The shot switches back to an overhead shot and everything is wet again.