When Kat is leaving the store and she asks Patrick if he stalking her, wait until she gets in her car. If you look in the window reflection in the store across the street, you clearly see Joey's red convertable sitting there waiting for Kat to get in her car. As soon as she gets in the car, you see the red car go into action and pull forward.

Editor's note: I haven't watched the movie in a while, but aren't you supposed to be able to see the reflection of the car? I don't really remember the relevance of this scene.