Wings were made for airplanes not race cars.
At least on a sprint car they have the power to pull the tin foil through the air.
Watching a winged mini sprint race is like watching a pavement race. Not saying pavement racing is boring but if you are afraid to steer right to turn left why are you on dirt?
Putting a wing on a D2 car would be like holding both the brake and the throttle to the floor.
The only logical reason I could think someone would want tin foil on anything smaller than a V-8 would be 1 they want a security blanket for when they get upside down or 2 they dont have any throttle control talent.