Revealing mistake: In the aerial shot where the Pantera explodes on the highway, you can see that it's a crude mock-up on some type of rolling trailer. Also, it appears to only be moving at 30 or 40 mph, which is WAY slower than the 160 mph speed indicated in the movie.
Cannonball (1976)
1 revealing mistake
Directed by: Paul Bartel
Starring: David Carradine, Gerrit Graham, Bill McKinney, Veronica Hamel
Factual error: Supposedly the Pantera was rigged to explode once it reached 160 mph. There are two problems here. First, a stock Detomaso Pantera could never reach 160, especially a smog-controlled "L" model with the old bias-ply Arriva tires, which is what they used in the movie. Second, the Dodge Polara police car that was tailing him closely and matching his speed, most DEFINITELY would not be able to achieve that speed.