I'm looking for an enclosed trailer big enough for my 11 foot T660. I'd prefer a 2-place clamshell, something inexpensive. Most clamshells that I see are 10 footers, with the occasional 11 footer. Am I safe in assuming I need a 12 foot clamshell? It seems like the obvious answer, but I'm new to enclosed trailers, and am really tired of having to brush snow off my sleds all the time.