I may end up going that route, but I am not convinced sticking a plastic disc on my dash is the way I want to go. I would much rather have it on a vent mount, or on a Pro-Clip in front of my dash. Part of my concern is theft, and a Pro-clip on the front of the dash is even harder to see than a dash disk on the top. Someone would have to be checking the car out from up close before they would notice it. Also, I drive a Tahoe and I have to put the mount up near the rearview mirror to make it reachable. Really sticks out in the parking lot and distracts the eye when checking the rearview.
I thought about making a smooth plate for the pro-clip, but it may stick out too far with the standard mount.
( I had a 510, then tried a Nuvi and am going to a 910 now, so i have had a couple in my car already, Bless Amazon's return policy)
Anyone else know the size of the ball?