Abstract: A sunshade device is transformable from a folded orientation into an unfolded, fully erected orientation supported on a surface. The sunshade device has a base panel having opposite first edges and supported on the surface when the sunshade device is in the erected orientation, and a pair of side wall panels. Each of the side wall panels has a first edge respectively connected to one of the first edges of the base panel along a connecting line disposed generally horizontal to the surface when the sunshade device is in the erected orientation. The side wall panels extend generally upright and are disposed in spaced-apart relation from each other when the sunshade device is in the erected orientation. A top panel has opposite edges respectively connected with second edges of the side wall panels opposite the first edges thereof for limiting a separation distance of the second edges of the side wall panels.