Abstract: Today when most passenger cars are fabricated without frames, many people are using vans and sports utility vehicles to pull trailers. These vehicles have improved efficiency and apparent power when equipped with a wind deflector. A wind deflector for such vehicles is disclosed which comprises a top member which is mounted on the rear portion of the vehicle and two side members having front side portions which extend downwardly from the top member along the sides of the vehicle. All said members curve outwardly from the front side portions thereof away from the vehicle. All members are molded from semi rigid plastic and have spaced braces on the rear interior side portion thereof. The top and side members are matably fitted together and releasably held together by buckles. The wind deflector is removably mounted on the vehicle using hook bolts, straps and bars which are fastened to the frame beneath the vehicle.