Revealing mistake: At the beginning of the movie, when Kowalski is chased by cops on motorcycles on a dirt road, in the shots from behind the Challenger you can see two people in the car.
Vanishing Point (1971)
1 revealing mistake - chronological order
Directed by: Richard C. Sarafian
Starring: Charlotte Rampling, Dean Jagger, Barry Newman, Cleavon Little, Victoria Medlin
Factual error: At the end of the movie the 1970 Challenger R/T that is shown crashing into the bulldozers is actually a 1967 Chevrolet Camaro at the time of impact. It's visible for just a few frames, from behind at impact (before exploding) and later as it stands on its nose, after the fire is put out. Note the plain steel wheels, painted silver in the latter shot.
Hitchhiker: Patiently. That's the only way to wait for somebody.