They think the air blowing their ears back is fun. They also get a better view.
Eric - To give you a more serious answer, I don't really know. Clearly there is some sort of a pleasant sensation that they get from it - whether it's the air blowing on their ears, the wind through their hair, or just the better view is hard to say. Whatever the cause, it is important that owners not allow their dogs to do this. Injuries are common when a dog gets its head stuck, gets hit by a passing tree branch, or just decides to jump from the car. Even dogs that have ridden with the window open for years may still decide to jump. Be safe and try to avoid those midnight trips to the animal ER!
(senior veterinary student)
(republished on 07/18/06)