At approxamately 31:47 into the movie, the Chief replaced the vans passenger rear tire, with a white letter tire, mismatched to the other white wall tires on the van, (not a slip-up, since it may have been the only tire he had for them) the slip-up occurs at approxamately 35:35 outside "Java the Hutt" cafe, during the fight scene, the passenger rear tire is white wall again, and at 45:21, the tire is back to a white letter tire.