A sprint car wing or wing assembly is provided. The wing, which is known as a top wing, includes a wing belly and left and right side boards attached generally perpendicular to the wing belly. The wing belly includes a non-uniform thickness along its width to create downforce for the car. The right and left side boards are positioned mostly below and above the wing belly to aid in the creation of downforce, and also to provide the car with a sideforce during cornering. The side boards include a flexible surface, which will curve or bow to create greater sideforce. The side boards also house mounting frames of the wing assembly to mount the side boards to the wing belly.