The city car category features two sizes: small and extra-small. Many buyers may simply stop at external styling, as all four cars have a look that will stir up some emotion. But if you’re a real urban dweller who fights a daily battle for parking, look at either the Smart or Scion. If you think you might carry more than one passenger or are willing to pay to get behind the wheel of a fun-to-drive car that can make the occasional road trip, think Mini or Fiat. They all get 37 or 38 mpg on the freeway, which is good but not great for such small cars.