Abstract: A self-deployable front air spoiler assembly mounted beneath a vehicle underbody, the air spoiler assembly comprising a laterally extending airfoil which in non-deployed condition is situated in a semi-concealed position. The airfoil is supported at each side of the longitudinal center of the vehicle on swingable links, each link being pivotally coupled at one end to the airfoil and at the other end to the vehicle underbody. The pivot axes of the links are substantially parallel to the airfoil. Biasing means interposed between the air spoiler assembly and the vehicle underbody normally biases the airfoil toward its deployed condition. As the air pressure against the front face of the airfoil increases as the speed of the vehicle is increased, the airfoil swings downwardly increasing the frontal area impacted by the airstream and restricting the flow of air beneath the vehicle underbody.