Not to tell you how to spend your money, but do you have a smart phone? And if you do, why not use it as your NAV unit? I have an Android device that uses Google maps for it's navigation and I have to say that it is more accurate than my Garmin (even after the Garmin gets it's map update). Also, the map updates for the phone are free. Get a holder for your phone and a charging cord and then spend the other $650 on some other updates

RL