Various embodiments of the present invention are directed to an air deflecting system positioned on an automobile and configured to produce an increased side force and/or a more favorable yawing moment when the automobile is cornering or is otherwise yawed relative to the direction of the free stream air flow. In one exemplary embodiment, the deflecting system comprises a downforce-producing horizontal rear wing located proximate the rear end of the automobile, the rear wing having an endplate on each end. In one embodiment, the endplates are angled or have cambered airfoil cross-sections such that they each generate an aerodynamic force towards the inside of a turn when the automobile is cornering.