My boyfriend's friend's dog jumped out of his truck while going 70 mph down the interstate. Dog lived with minor injuries (all things considered) and the windows are no longer rolled all the way down when he's driving. Some people have to learn the hard way, thankfully this dog didn't lose her life for him to learn it. I never leave my windows down enough for my dog to even get his whole head out. I always imagine him jumping out after a dog or something. Totally terrifying and I couldn't leave a dog loose in a bed, no way.