Don't ever adopt the metric system. Also why is it whenever Americans talk about doing the metric they always leave an exception to tempreture? Centigrade is like the only metric measurement that is based.
Europeans love to be haughty over Americans about them not using the metric system, but they've never had the misfortune of using a GPS with an American Accent.
"In 600 Meters. Turn left". That's just painful to hear, the R is not supposed to come after the E.
If America ever adopts the metric system, all the GPSes in the world would switch to an american accent as a cost saving measure, since not they no longer have to distinguish between feet and meters.