A floor assembly (28) for a cargo space (24) of an automotive vehicle (20) includes a floor support (32) adapted to be mounted in the cargo space (24). A floor panel (30) is mounted on the floor support (32) for movement along a predetermined path of travel from a first position totally within the cargo space (24) to an extended position at least partially outside the vehicle. Locking mechanism (40) releasably locks the floor panel (32) in the desired position, locking mechanism (40) may also be capable of locking the floor panel (32) in several intermediate positions between the first position and the extended position. The locking mechanism (40) preferably includes locking detents (60) in spaced apart relation along the path of travel, and a locking lever (44) engageable with any one of the detents (40) to lock the floor panel (32) in a selected position.