An air guiding system for a vehicle, particularly a passenger car, that is arranged in a rear area of the vehicle and has at least one central main air guiding element displaceable from a moved-in inoperative position into a moved-out operative position. Lateral auxiliary air guiding elements are displaceable together with the or each central main air guiding element. The lateral auxiliary air guiding elements can be rotated like a folding knife with respect to the or each central main air guiding element in order to change them from an also moved-in inoperative position into an also moved-out operative position.