Continuity mistake: The two Lamborghini women get stopped by police. The one in the red suit is on the right, with her front zipper up. In the next shot the other race contestants zoom on by, and the two women are shown from behind. In the next front shot, her zipper is down. The next shot from behind, show more race contestants zooming by. The next front shot, her zipper is up again, then she pulls it down to pull out her driver's license for the officer.
Continuity mistake: We can see Sammy Davis Jr. as he slits Burt Reynold's car´s tires. Later we can hear Reynolds as he says that they lost more than 2 hours by fixing the damage. But how comes that at the petrol station, Reynold´s car leaves even before Sammy Davis Jr. and Dean Martin arrive there?
Continuity mistake: Bert Convy's character is wearing a Goodyear ballcap and is riding his motorcycle down the motel corridor. He crashes into the Cannonball Pub, he is now wearing a helmet. As he launches himself over the stairs in the motel lobby, he is back wearing the Goodyear hat. (00:30:58)
Continuity mistake: JJ and Victor's ambulance's engine sounds are dubbed, and a few times you can hear the sound of shifting a manual transmission when the ambulance is shown to have an automatic.
Continuity mistake: In the scene where the GMC pick-up truck jumps the train, you see the front of the truck being damaged during landing. Later in the movie, the truck is undamaged.
Audio problem: When Mel Tillis and Terry Bradshaw are trying to "re-tune" their race car, when Bradshaw tells Tillis to "hit it one more time", the car makes the distinct starting sound of an older Chrysler when the car was a Chevrolet. Also, how does Tillis starts the car? He has one hand on the steering wheel and his other hand is on the doorframe.
Factual error: Looking at the dimensions of the low-loader and the dimensions of the ambulance, Victor is laying at 90 degrees to the ambulance as we see a shot from the front of the vehicle (over the lower wishbone). There's no way that he could mend the transmission without his legs sticking out the tarpaulin and not being seen.
Continuity mistake: After the girls in the Lamborghini are pulled over, they get passed by several other Cannonballers. Blake's Ferrari passes them twice.
Deliberate mistake: In the last sprint towards the finish line, before they have to race on foot, the Lamborghini passes Fenderbaum and Blake. The red Ferrari they are supposed to be driving, is on the bed of a truck being towed. Notice the height difference between the two cars; about ten seconds later the two cars are pretty similar in height. (01:23:05)
Revealing mistake: Several times in the fight scene near the end, it is painfully obvious that punches are thrown by the characters and are heard connecting but never actually touch anyone.
Continuity mistake: After the Sheik pulls up to the restaurant and the car hop brings out his food, he pays the girl by sliding a ring onto her finger. When he pulls away the first time, you can see that she has a wad of cash in her hand. The problem is, he hasn't given the money to her, yet. In the next shot, he backs up and as he says, "Get a physical," he places the money in her hand.
Plot hole: Mr. Foyt spies on J.J. and Victor to find out more about the Cannonball, yet fails to recognize them when they stop to pick him up.
Continuity mistake: In the scene where the pickup truck jumps over the train, you can see the passenger's cowboy hat fall off on impact, but in the very next scene he is shown still wearing it.
Continuity mistake: While the police are chasing the Lamborghini during the opening credits, a car passes both of them on the right side as if it were England. (00:03:35)