Their ZIP codes.
Live in a location that has a high crime rate? You'll pay extra, in some cases thousands of dollars more per year. The highest rates in the country can be found in Brooklyn, New York where annual premiums can run as high as $4,133. Take the same make and model vehicle to Webster, New York, a little town on the southern shores of Lake Ontario, and the price plummets to $861 per year.
Brooklyn may be the most expensive borough of New York City, but the city with the most expensive rates overall? Detroit, Michigan.
For more on how ZIP codes affect your insurance premiums, check out Business Insider.