Abstract: Disclosed are improved lightweight rear fairings that automatically retract when the rear doors of the trailer are opened. The fairings preferably each include rearwardly extending arms that stretch back from the hinged trailer doors to sheet rollers. The sheet rollers apply tension to fairing sheets that are secured to both the rollers and the sides of the trailer. The arms are able to rotate relative to the rear doors of the trailer, however rotation limiters restrict the amount that each of the arms may rotate towards the hinge of their respective door. Rotation of the arms away from the door hinges is not limited such that the arms may be rotated away from the hinges until they are flush with their respective doors. The fairing sheets are secured to the sides of the trailer at positions that are substantially forward of the rear doors such that even when the rear doors have been fully opened the rollers are still located rearward of the forward attachment points of the fairing sheets.