If your fc has the door at the rear then the jockey wheel mast is really good and very stable, if the door is on the side the bed will overhang the jockey wheel and you won't be able to use that sort of fixing.
We bought this little magnetic aerial from ebay and it works everywhere.
http://www.ebay.co.uk/itm/122043668995?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
Amazing family weekend with old steam engines, classic car displays, market stalls, and full catering and bar. And camping on site - Save £25 by booking in advance.