Inspired by something he saw in a horse-drawn carriage, Indy racer Ray Harroun installed a rear view mirror on his car to replace the ancillary rider, a mechanic, who would normally accompany a driver. Most historians credit Harroun with inspiring the invention of the war view mirror, even though he admitted he borrowed the idea. The rear-view mirror is like your thumb. You never think much of it until it doesn’t work they way you expect. Try flipping it to the wrong angle for five minutes and see if you don’t go nuts. It’s hard to imagine that cars once