My dog, Roxy, who is becoming Ask Patty famous, is always looking for a game. Recently while driving, she decided she hates/loves/wants to be obsessed with our windshield wipers.
Here she is being an absolute nut (sorry it is a little dark at first):
I know, it's almost sad really. She is getting help. Apparently there is an entire group of animals with this same problem. Check out Dogs Barking in Cars for more of them.