A method of forming a trim panel is provided comprising molding an interior panel substrate including a main body portion, a lock portion molded as a portion of the interior panel substrate and having a locking element, a first living hinge positioned between the lock portion and the main body portion, a lock engagement portion, and a second living hinge positioned between the lock engagement portion and the main line portion. The method molds an exterior cover stock, including a belt line skin portion, onto an outer surface of the interior panel substrate. The lock portion is rotated about the first living hinge to trap the belt line skin portion between the lock portion and the lock engagement portion in order to create a mechanical skin lock. The lock engagement portion is then rotated about the second living hinge towards an inner surface of the interior panel substrate.