Continuity: The headrests in the Volvo keep changing from the old 1985 and earlier style, to the more squat 1986 and later style. This is due to the fact that two of the cars were used throughout the movie, one of which broke down during filming.
Factual errors: When they turn on the lights in the dark Costco, it instantly becomes brightly lit. In reality, HID lamps are very dim when first switched on and require several minutes to warm up and reach full brightness.