After Wesley has Ketchum destroy Strodenmire's car dealership in Jasper, MO. with the big wheel truck, you can see a highway sign behind Dalton that reads "Los Angeles" "Bakersfield", accompanied by mountains.
Dalton is fighting one of Wesley's goons in the old man's house. The bad guy has a large knife, but D soon relieves him of it. A couple of seconds later, it is back in the goon's hand, and Dalton uses the same move to take it from him again.
After Dalton has put the tires into the car the boot lid wouldn't obviously get closed as there are to many tires in it. So the next camera perspective shows only Dalton closing the lid and doesn't shows the tires anymore.
Early in the movie, Dalton's Mercedes is shown with flush headlights and cleaning wipers. When he's working out in the barn, it's shown as an older US model with recessed sealed-beam headlights and no wipers.
When Dalton interrupts Steve and the girl in the break room, Steve pulls his underwear up in the shot from the side. When Dalton walks out of the room and it goes back to the shot from the front, with the girl in front of him, Steve's underwear is still down.
When Wesley's henchmen are pulling away in the red Mustang after trashing Red's Auto parts, a sign identifying one of the buildings across the street as "California Tile and Home Center" is clearly visible.
The Ford station wagons crushed in the car dealership scene are purported to be new cars in the movie...but in fact when the film was made they were all about 4 or 5 years old at least, possibly as old as 1979 models.
When the Businessmen are all shooting Brad Wesley in his house, Kelly Lynch is standing next to Emmett, and reacts as the a shot is fired. She then reacts again in a similar fashion, although no further shots have been fired at that stage. She was anticipating the shot that followed few seconds later.