When Rubber Duck and Violet the waitress are walking towards RD's truck at the diner, you can clearly see that Violet's pantyhose has a huge tear and run in one leg, but when she climbs out of the truck after the fight, her pantyhose are flawless and new.
Throughout the film, Rubber Duck's truck has a grill guard. In the scene after his and Pig Pen's trucks have crashed through the jail, the grill guard is missing when the truck pulls out. Yet it's back on there for the rest of the movie.
Spider Mike's afro occasionally changes from a parted afro (which it's supposed to be) to a smooth afro.
When the convoy has to stop because of the school bus, Pig Pen runs into an ice cream truck; the back doors on the ice cream truck swing open and one falls to the ground. In the next shot the door is still on the truck.
After the trucks crash into the jailhouse, the black Mack truck pulls out of the rubble with lots of obvious damage and dirt. The damage subsequently disappears and reappears between shots.
At 39:30, Lyle, a county deputy, would not be permitted to drive an Arizona Highway Patrol officer's car when the officer is still operational.
When Rubber Duck's truck falls from the bridge, the drive shaft to the rear axles is missing.
The sports car that Lyle commandeers does not have a rear view mirror.
The engine sound of the Duck's truck changes repeatedly - i.e. at one point it's a Detroit Diesel, then Cummins, then Cat, and at one point a Chevy smallblock.
On numerous occasions dialogue is dubbed, and sometimes clearly mismatched with mouth movements, and lines added when the actor isn't actually speaking.
When Sheriff Lyle's squad car gets sandwiched by two trucks, the camera used inside the car is mounted in the rear, but its size was such that it couldn't be positioned out of shot of the second camera mounted on a flatbed trailer in front of the action.
In the start of the movie when the Jaguar passes by The Duck, we can clearly see the reflection of the camera man, on the side of the truck.
When the trucks destroy Sherriff Alvarez's town, some of the buildings a clearly mock ups, you can even see daylight through the walls.
At 50:22 (as per YouTube) the caption says "New Mexico" and "I-40". However, the shot is from I-25 just west of Isleta Village. That particular profile of Sandia Crest is only visible from this vantage point, and other features in the picture also give it away: the small escarpment to the right of the truck, and the small mountain in the far background on the left (Google maps, street view can be used to verify).
At 51:18, the trucks run through a weigh station without stopping. There was no need as they planned to not stop, so they could have stayed on the highway to run it, rather than turning in and busting through.
Rubber Duck is known to transport highly explosive chemicals, but the US Border Patrol members still shoot at the trailer in the climax. They should know what is in the trailer like every other authority does..