Originally Posted by TitaniumStick
They were originally put on race cars that ran the same team colors to tell them apart at a glance.
In the Corvette world, they are called hash marks, pit stripes, or Grand Sport stripes. I have seen them in vintage racing pictures on a variety of marques, including Shelby Cobras and early Corvettes.
What about origination? Any timeline? Pre-Mustang adoption?