In the scene where Danielle steals Matt's underwear after he strips in the street, she stops to let him in the car. When he tries to get in and the door is locked, he puts his hand on the door, partially inside the car, meaning the window is down. When she unlocks the door and he opens it, the window is clearly rolled up. Then when he gets in and closes the door, the window is rolled down again. It's magic!