You should be fine with an inflatable or the Crack of dawn roof rack but if you're interested in checking out how a roof rack + kayak looks on a mustang, i attached a link for you.
http://www.carrackadvice.com/yakima-...-carry-kayaks/
In my opinion, a fairing is not needed. I found this on CL,
http://losangeles.craigslist.org/wst...687574710.html