1.) Are you afraid of gas pumps, of your throttle, or of lightening your wallet some? Then yes; rent a P.O.S. econobox from whoever has the cheapest rates, the best insurance and the crappiest cars (so that you can hoon and abuse them to make up for their lack of go).
2.) Are you, or is your car, a garage queen? If not, grab yourself a pair of balls and hit the road! Mustangs were built for two things, really - finding speed on the straights and blasting petrol-heads half way across the country in affordable comfort and kickass speed.
3.) Do you, or anyone involved in your trip, weigh in excess of 350Lbs, have sixe legs and a rectangular torso? No? Then you'll be fine.
Suck it up! Do the miles!