Abstract: A wind deflector system for flat-nosed vehicles (C.O.E.--cabin over engine) composed of two complementary stages. The first stage consists of a flat upwardly-extending wedge-shaped cone which extends from the front of the flat-nosed vehicle and which deflects air around the cabin while the air flow applied to the front is diverted upwardly to the top of the cabin. At this point the second stage of the system, which lies on top of the cabin, comes into effect. The second stage, which is affixed to the roof of the cabin, enables the diverted wind from below to pass around and over the following trailer while a movable wing extension at the rear enables the driver to direct the course of the following wind.