This wing is set at a high angle of attack. Note the panels are offset in height from the right to left sides. It is the intent of the lower right side panel to allow the upper portion of the wing to receive air as the car slides somewhat sideways in the turns. What is forgotten is that in order for the wing to work, the air must flow efficiently over the top and bottom of the wing. The panel obstructs the flow under the wing where the lift is created. Furthermore, obstructions under the wing such as the flow off of the front wing, rollbars in close proximity to the wing, and the braces all decrease the usefulness of the wing. Its real function is often as a flat panel device rather than a wing. And as a high drag, high CG component that causes a high amount of load transfer.