N. B.

     For whatever it is worth, the most likely source of the phrase "roll down the (car's) window" dates back to when automobiles had canvas tops, and flexible isinglass side windows were an option.  Stored rolled up, you would roll them down to keep rainwater from splashing in while retaining some visibility.

     Hardtops came along with cheaper, mass-produced cars, and the crank mechanism to raise and lower side windows wasn't far behind.  You might crank your window down, but the older phrase was already there, and you were turning a thing, after all, so you rolled them down.

     I buy older cars but technology keeps on cranking, and I have been using a switch to "roll" my car windows up or down since my first Lexus small SUV, the same way most people already had for several years.

     Inspired by tab-clearing here and a blog post here.