Other mistake: When Sandy goes to the gas station, where his card is declined he tells the clerk there is something wrong with pump 5 but if you watch, he is parked at pump 8.
Continuity mistake: In the shot where the car gets hit by the tractor trailer you can see the car had been painted to match the other gold Fords in the movie. The car was originally red but painted gold. The deck lid flips and is red on the under side. Also, during the high speed chase I noticed the same silver Chevy HHR about 5 times.
Factual error: When Sandy and Diana are leaving St Louis and supposedly driving to Denver they are headed east into Illinois with the Arch behind them and to their right.
Continuity mistake: While hitchhiking, the truck they try to get a ride from goes one direction, and when they start walking they go the opposite way.
Other mistake: When at the gas station filling up the Caprice you notice the gas pump isn't actually doing anything.
Answer: Atlanta, Georgia.