Abstract: An insert panel is installed within an opening of a trim panel. The insert panel has at least one integrally molded flexible hook member for yieldably hooking onto the walls of the opening to retain the insert panel within the opening. A retainer tab is formed integral with the trim panel and extends into the opening to underlie a portion of the insert panel. The retainer tab has a flexible finger extending into proximity with the hook member to block the hook member against movement in the direction to unhook from the wall of the opening. The insert panel may be removed from the trim panel by resiliently flexing the retainer tab to unblock the hook member so that the hook member can be unhooked from the wall.