The little circle crosshair icon showing your present location on the nav screen will just start tracking rapidly across the country and keep beeping annoyingly as it tries to recalculate a route. This is done without any input from me. It will still alert me to an upcoming turn, as well as the final destination, but for some reason, my car sometimes thinks I'm somewhere that I'm obviously not. If it happened every time, I'd take it to be serviced, but it's intermittent. I'll do the update when I get the chance and then see if it still happens. If it does, I'll try to capture video of it.