When Jim Bob is explaining the modifications he made to his car so Mike could drive it, shots of Jim Bob show him sitting in the driver's seat and he has his arm on the driver's side door. In all the shots showing Mary Ellen and Mike from inside the car, it is obvious there is no one in the driver's seat. No arm is on the door, and a few inches of the inside of the door are visible.
A paraplegic person cannot stamp their foot on the floor and say damn it when seated in a wheelchair.
Too hard to swallow John-Boy being "really close" to Paxton the bully who played nasty pranks on him and nearly got him kicked out of college.