I leave mine (an LG VN220 "Exalt" clamshell -- I refuse to own, much less carry, a full-on smartphone) in my pocket. I can, after all, place and answer calls via the Bluetooth.
Now on the other hand, next month, I'll almost certainly be looking for a mount for a portable GPS navigator. I already installed a hidden, dedicated 12V socket for it when I tapped power for my "flap ajar" alarm.
James H. H. Lampert