Whether you drive a pickup or a roadster, you probably have your Labrador in the seat next to you at least some of the time. Dogs have their own special way of marking their territory...but maybe you can head him off by showing him you care with this "LAB DAD" sticker. Put it on the bumper so it's just his height or put a couple on the windows so he always knows he's welcome in your vehicle.
Stickers are 3" x 5" and are designed for car bumpers or windows, so they will come off without removing a layer of paint. Just don't stick it to your Lab -- we're not so sure about hair.