Locking sunshade system

In a disclosed embodiment, the interior sliding sunshade portion of a "moon roof" (12) of a vehicle (14) is provided with an improved system for locking an overhead sunshade (10) in an open or closed position while allowing it to slide relatively freely during sliding movement. The sunshade (10) is provided with a spring-biased cam locking system that reduces frictional contact between the edges of the sunshade and the side tracks (16,17) within which it slides when the vehicle operator manually slides the sunshade (10) to an open or closed position. The improved system further includes a mechanism for engaging and opening the overhead sunshade (10) automatically when the corresponding overhead window is opened.