Abstract: A closure panel mounting for a window opening of a vehicle body structure includes a U-shaped three sided recess into which the panel is slidable, with a fourth side of the closure panel engaged by another closure panel included in the vehicle body structure. In a first embodiment the panel is slid vertically down into tracks extending along the recess, and a top panel has an edge engaging the fourth side of the panel. In a second embodiment, the recess tracks extend horizontally and the panel is slid into the recess from the rear, a vehicle tailgate engaging the end of the panel when swung closed to secure the closure panel in position.