there's this:
http://www.ebay.com/itm/380921775726?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649
but i think it's for a ruf front bumper. i was just going to use a hacked-up Rubbermaid container shot black and either plastic weld or hot glue in place. or perhaps some thin lexan from home depot.