15% of the budget was just on the cars. By the end of filming, all but 2 were destroyed.
Portions of the film, particularly Arnie's neighborhood, were shot in the same South Pasadena neighborhood that director John Carpenter used in Halloween (1978).
To simulate the car regenerating itself, hydraulic pumps were installed on the inside of some of the film's numerous Plymouth Fury "stunt doubles", a mock-up in plastic that looked more like metal on camera than actual metal as it bent and deformed. These pumps were attached to cables, which were in turn attached to the cars' bodywork and when they compressed, they would "suck" the paneling inwards. Footage of the inward crumpling body was then reversed, giving the appearance of the car spontaneously retaking form.
Stephen King chose a '58 Plymouth Fury for Christine because it was a "forgotten car." "I didn't want a car that already had a legend attached to it like the '50s Thunderbird."
The movie playing during the drive-in scene is Thank God It's Friday (1978), which features a running gag where a character's cherished automobile keeps getting damaged (both deliberately and inadvertently) throughout the film.