Another thing that cought me by surprise is inability of the Nav to extrapolate the car dynamics when gps link is temporarily unavailable, particularly after you enter a tunnel. I don't understand why it jumps from the tunnel I enter onto neighboring streets, even though there is exits along the way. My old Acura was much better at it, and was moving me along the tunnel very accurately based on the speed of the car without losing track. this issue is particularly bad when you cross from Manhattan to Brooklyn over the BBT and NAV shows you 4-5 blocks away from your actual location.