I saw a product in a website, I found it interesting as I saw such a product for the first time.
If you have a dog it may be very useful.
The Auto Window Bumper is a headrest cushion for dogs. Simply adjust the window to the desired height and slide on to the top of the window. Metal clips inside the pad holds the bumper to the window. Made with a nylon Cordura for durability.
For more information check their site.