A retractable curved air dam assembly is provided for improving the aerodynamic characteristics of a motor vehicle. The air dam assembly is segmented to include a plurality of panel members each adapted to pivotably attach to the underside of the front-end vehicle structure. The panel members are configured to selectively transition between a deployed position, in which the panel members are preferably in a generally vertical orientation, and a stowed position, in which the panel members are in a generally horizontal orientation. The panel members are shingled (i.e., partially overlapped) such that pivoting a center panel from the deployed position to the stowed position thereby pivots the side panels to the stowed position, and such that pivoting a side panel from the stowed position to the deployed position thereby pivots the center panels to the deployed position.