On top of the parking garage, the owner of the truck that gets pushed over the side of the building is first pictured wearing a cap with a rebel flag design and in subsequent shots of the same scene his cap has an American flag design.
The same background vehicles are used repeatedly throughout the film during major action sequences on the streets. Most obvious are a red Mercury Bobcat, beige Ford Thunderbird and red Ford Granada, which appear, along with other vehicles, multiple times during the hovercraft chase, and earlier in the parking garage scene. Vehicles that are hit and damaged show up later parked or representing other vehicles, including the Dodge Diplomat police cruiser struck by the station wagon at the intersection; this reappears shortly after as the police unit hit by the hovercraft along with Harrison's unmarked car (identical damage from the earlier scene is visible). Furthermore, two of the unmarked police cars (the red Plymouth Caravelle and gray Chevrolet Caprice) are inconspicuously used as parked vehicles several times throughout the hovercraft chase, most obviously at the beach where Keung runs across them to jump aboard the craft.