I'm planning to make a road trip and worried about a flat. I was thinking about buying a tire mounted and inflated on a wheel (America's tires, Big-O-tires) and carrying it with a jack (All costs under $250 altogether). Sure, I'll have to put the tire in the back area behind me and the whole thing will definitely add weight but no more than one passenger. I'll be driving alone. Is this a dumb idea?