ThinkGeek has released a Moving Tail Kitty Car Decal that, when applied to the rear wiper area and turned on, makes it looks as if you have a happy or grumpy cat wagging its tail on your back windshield. The decal kit (2 kitties and 4 tails) is available to purchase online.

Get some animal action on your car in a way that isn’t illegal in most states with the Moving Tail Kitty Car Decal. Designed for cars with a rear window wiper, this whimsical kitty comes in two flavors: Happy and Grumpy. You get both! (Kids, do not assign Happy and Grumpy to your parents. Let them pick. Just trust us on this one.) Application is easy: clean off the surface, stick down the vinyl decal, and smooth any bubbles out with the side of a credit card. Then turn on your wiper and watch the kitty’s tail swish swish swish!