An air guiding system for a vehicle, particularly for a passenger car, is arranged in a rear area of the vehicle and has at least one central main air guiding element that can be displaced between a moved-in inoperative position into a moved-out operative position. Lateral auxiliary air guiding elements are displaceable together with the at least one central main air guiding element. The lateral auxiliary air guiding elements can be displaced while enlarging the transverse dimension and while simultaneously enlarging the longitudinal dimension of the main air guiding element or the air guiding system from an also moved-in inoperative position into an also moved-out operative position.