I recently passed a car that had a golden retriever standing on the passenger side of the front seat of the vehicle with its head and the upper part of its body sticking out the window. The dog was thrilled and I'm sure the envy of every dog it passed that was sitting in a booster seat (like my Pomeranians) or strapped in the back seat, for their protection. Yes, it is fun for dogs to stick their heads out the window; I imagine they think they are running that fast. What a thrill for them! But, what a hazard to their health, and in particular to their eyes not to mention their entire bodies.
Think about when you are riding a bike, or a motorcycle without a windshield or helmet. For the safety of the motorcyclist eye coverage is required by law because if something blows into your eye, whether debris or bugs, you can end up in a serious if not fatal accident. That same debris is flying through the air and can end up in your dog's eye.
When I used to work in Cambridge, MA, the winds were so strong around the square that my office building was located in, and some kind of construction was always going on, that one time a piece of grit got lodged into my eye and sent me to Mass Eye And Ear to have it removed. And I was just walking down the street! Think about driving at 40, 50, or 60+ miles per hour and that same piece of grit ending up in your dog's eye. So, the solution would be to get a pair of doggles for your dog's eye protection.
Another story: a friend used to let her dog hang out the window and one time it saw something that made it leap out of the window, injuring its front leg. After several months of dragging the injured leg around she finally made the decision to have the leg removed. Yes, dogs are adaptable to any situation they find themselves in, but why put them through that, not to mention the vet bills for the surgery.
So, yes, even though it is great fun for your dog to stand on the seat and hang its head out the window, you might want to reconsider and think about the welfare of your dog instead of just the fun he is having.
Help Shelter Pets Golden Retriever dog card sold in The Card Shop