You've heard it, you've said it, you've been there. And the reason the expression reads exactly that way is no doubt explained in an article (in my queue for my online editing gig) I simply can't bring myself to click on: "Reasons Why a Fly Doesn't Smack Against the Back Window of a Car."
Call me a coward if you will. Say I have no sense of adventure, that I'm incurious. I fear if I were to edit this article, I would tell the author, in my rewrite request, to add a warning relating to what happens if you put your car in reverse and put the pedal to the metal.