The Plymouth Duster I was a high-performance concept car of the Road Runner in the late 1960s. It featured the usual low curved racing type of windshield and had airplane-type flaps on the top and sides. There was a set adjustable spoilers on the side of the rear fender near the gas tank filler cap to prevent side-to-side yaw when slipstreaming in a race, with two more of them on top behind the driver, plus spoilers in the front rock shields to…