When Abby and John pull up to the hotel in Oklahoma, the front license plate on the car is missing. When they drive into Chicago at the end of the trip, there is an Illinois plate on the front of the car.
When Carter and his girlfriend arrive, his girlfriends dog knocks over Abby's coffee cup. When Abby walks into the building in the next shot she sips from her coffee like nothing happened.
When John picks up Maggie to carry her to the car, she utters one last "I want to stay!" but her mouth doesn't move.