Does it cover the screws? If so that isn't really considered a seal it is more of a trim piece. On Airstreams it is known as insert trim. It is a shaped vinyl pieced that comes in a variety of colors, widths and shapes.
Aaron
__________________ There is madness to my methods
2015 Coleman CM16FBS(traded) 2016 Concord 300DS
2015 Ford Fusion Hybrid following along