Shading device for motor vehicle and corresponding motor vehicle

The blind, which can be moved between retracted and deployed positions, consists of a panel (10) with one or more stiffening ribs (11) that hold it in a predetermined shape when deployed. The ribs, measuring e.g. 1 - 3 cm wide and 0.2 - 1 cm thick and spaced at 15 - 25 cm intervals, are made from a supple material applied directly to or shaped from the material of the blind. They can be fixed in place by adhesive or welding, or made by over-moulding or extrusion; they have a cross-section in the shape of a policeman's helmet, and can be made from a compressible material such as an open-cell foam, or an incompressible material, optionally reinforced with plastic or metal.