Vehicle drag reducer

A drag reducer for use on a vehicle having two side walls each having a vertical rear edge adjacent a vehicle end, said vehicle further having a roof and a floor each having a rear edge adjacent said vehicle end, said drag reducer comprising two flat side panel assemblies, hinge means pivotally connecting said side panel assemblies to said rear edges of said vehicle side walls, said side panel assemblies converging and having edges meeting at a location spaced from the vehicle end when said drag reducer is in a first position, means for connecting together said meeting edges when said drag reducer is in such first position, top and bottom closing panel assemblies, means connecting said top assembly to said vehicle adjacent said roof rear edge, means connecting said bottom panel assembly to said vehicle adjacent said floor rear edge, said closing panel assemblies extending in the same direction and abutting said side panel assemblies when said drag reducer is positioned in said first position, said closing panel assemblies having edges in contact with abutting edges of said side panel assemblies whereby said side panel assemblies and said closing panel assemblies form an enclosed drag reducer at said vehicle end, catch means releasably connecting said closing panel assembly edges to said abutting edges of said side panel assemblies, and means including said hinge means for positioning said drag reducer in a second position wherein said panel assemblies are collapsed, said hinge means comprising hinge-slide means, said flat panels swinging on said hinge-slide means between said first position and a position with said flat panels parallel with said vehicle side walls and thence sliding forward along rail means attached to said vehicle side walls to said second position wherein said flat panels are substantially flush against said vehicle side walls.