When the car crashes into the tree, it is ~50 m from the body from the road. When they walk back to the body, the man is now much closer (~20m) to the car.
When Sheriff Angela looks up Maynard's police file, it says the arrest date is in 2012, despite the film being actually set in 2003, shortly after Wrong Turn 4: Bloody Beginnings (2011).
After the hillbillies cause the power outage in the city everything is without power. But the festival is going on (with sound and lightning) and the football field has also power for the floodlights.
The mutants attach a chain to the base of the phone tower. There is no way their truck will pull down a steel pole with pretty much a zero angle of force.
The original town massacre was on Halloween 1817. Halloween was not celebrated in the US until the mid-late 19th century.
When the hand of the jogger is chopped off and the camera focuses on it on the ground, the fingers are opening and closing spasmodically. But, the fingers of the hands are controlled by muscles in the forearm, which is not attached in this scene.
After being beaten unconscious, the outline of the stunt-padding she wears is easily visible beneath Angela's shirt as he drags her back toward the sheriff's station.
When the Sheriff shoots Three Finger, her aim is above the mid-line, yet she hits him in the thigh.
At the start of the evening, there are many festival goers around town. Later, the streets are completely empty and no shops are open. Even allowing for people attending the 'festival', it is totally implausible that everyone went there and the entire town then shut up shop for an important money-making event.
There are deputies at the festival, yet they never once radio the sheriff to check in. They don't even respond when the mutants blow up the shop.
While in the motel room, a group of college kids plan to go to the Mountain Man Festival in town in WV. Julian sums up that 4 tickets $90 each will cost a total of $260. It would of course total to $360.