Here are the two edge sections. Both were heavily cracked due to the fact that factory molding process injected very little plastic on the ends of the panel. The main area of the valance is about 3/8" thick while the outer edges are only about 1/16" thick. I had to reproduce a missing section from one end as evidenced by the different color of the polyurethane material in the lower photo. I also heavily back-filled the thin areas around the edge so now they're about 1/2" thick:
