Abstract: In a motor car with a flow stepped tail and air-conducting means in the form of a wing-spoiler combination, the flow stepped tail is constructed with an angle of inclination of the tail window which ensures a flow down from the rear edge of the roof and over the tail window free from flow separation and the wing (5) is disposed offset in front of and above the spoiler (6) secured to the tail in such a way that it is located in front of and above the area (18) subject to flow separation. In this connexion the wing (5) has a broad nose rounding (15), is arranged with its convex curvature (16) towards the tail window (3) and is disposed in an optimum position (28) and at an optimum angle of incidence (29). The wing (5) may preferably be connected to the spoiler (6) to form a structural unit by way of arms (7) running upwards and forwards along the frame of the tail window (3).