Duel (1971)

Continuity mistake: On the truck cab's rear window, there is some sort of air conditioning unit installed. In some shots, such as the gas station scene where David Mann is on the telephone, or the railroad crossing scene, the air conditioning unit has a support structure to hold it in place. In the rest of the film however, there is not any support structure to be seen.

David Mann: That truck driver's crazy, he's been trying to kill me, I mean it.
Bus Driver: Well, mister, if I was to vote on who's crazy around here, it'd be you.

Trivia: Steven Spielberg "interviewed" over 100 trucks before finding the forboding, evil looking one for the movie.