Watch the scene where Mack(John Goodman) drops the carpet tacks and the Russians run over them. First, the tires hit them and one of the hubcaps flies out, then their car flips over and all the hubcaps on the tires go flying(including the first one). Yet in the next shot where the car is skidding on its roof, all the hubcaps are perfectly intact(and of a different make!). Then, when they've stopped skidding and the Russians all get out of the car, the hubcaps are all gone once again!