While at speed on a four lane highway I accidentally bumped the shade that came with my previously owned Nav V, dislodged it, and down the road it went. Quickly pulled over, parked, walked back but only found one piece of it. On the plus side, there are good people near Cambridge, OH; one guy pulled over while traveling the opposite direction, crossed the highway via an emergency turn around and stopped to see if everything was ok. Another lady went past us, pulled over and backed up to check on us. The one I had was hard plastic that snapped on. Other than being easy to knock off it worked well. Any recos for another one? And can anyone confirm that a Nav V uses the same "box" as a Zumo 550?