A mounting clip, mounting an element to a structure having trim with a thickness, includes a body having first and second legs with a gap therebetween sized for receiving the trim. The first leg is positionable against the element. The first and second legs have aligned, possibly threaded, through holes. The element can be fastened to the trim through the clips without penetrating the structure. The first leg has a distal end which can be curved to act as a trim engagement element. The mounting clip and fastener structure, such as a threaded fastener, can constitute a mounting clip assembly. A PV panel wire cover assembly includes a wire-covering housing having open ends and a mounting flange. Closed and open end cap mountable to the open ends prevent access to the housing interior when the housing is mounted to the panel, the open end cap having a wire passage opening.