Plot hole: When the Griswolds are at Wally World, supposedly the only people there are the guards. Who operates the rides for them?
Suggested correction: The guards also knew how to operate the rides.
Original mistake is correct. There were only 2 guards. 1 they kidnapped. The other they left lying like a dog until he could call the police. Therefore, there was nobody to operate the rides. Besides amusement parks don't train security to operate the rides.