I have the Navigon 8100T that has the antenna in the stalk that the LCD mounts to. If I didn't use the stalk, I would have to install an external antenna in order to reposition the unit on the dash.
It is big, voice activated, and presents lane control views. I hwill have to hide the 12v plug somewhere. Maybe go thru the side panel next to door or maybe thru the base of the pillar?