The flaps are stowed during normal vehicle operation.
How do roof flaps work.
In 1994 nascar introduced roof flaps a safety device designed to keep cars from going airborne and tumbling over the track.
Roof flap spacers are metal disks that sit in the tray and give the roof flaps something to rest on so that they remain level with the roof surface.
Before this when the cars spun out at high speeds more than 195 mph 324 kph they would often fly into the air once they had rotated about 140 degrees.
A roof flap is an aerodynamic feature on race cars mainly stock cars which functions as an emergency spoiler to prevent the vehicle from lifting off the ground.
Roof flaps are two plates located on the roof which measure 12x8 inches 30x20 cm and are depolyed as the car is either sideways or going backwards at high speeds.