When Jewel brings the car home to show Randy, it is all covered in dirt and soot. Then as Detective Dehling pulls up in his car, you see the back of Jewel's car is shiny and clean. This is before the infamous "wash" scene, which happens as Detective Dehling is leaving.
When Randy discovers the DVD player in Greg's bedroom he opens the tray and we get a close up of a white, blank DVD, but a red, titled DVD (see Trivia) is in the tray that is shown opening and closing repeatedly after the accident.
When Randy asks Jewel what her favorite thing in the world is, he lifts his right hand to drink from the cup. In the next shot, the cup is in his left hand.