(at around 1h 22 mins) After leaving his car in the cornfield, the family runs into the house. Outside the burning house the car appears in the driveway.
(at around 8 mins) During the supermarket scene where Courtney and the boys were running out the building, Courtney tosses the car keys to Dylan but when the camera switches to outside the building, it's Zach who has the car keys and is able to start the ignition for Courtney. Not Dylan, who was handed the keys. It wouldn't have been possible for Dylan to hand Zach the keys within that time.