I added one last piece to the instrument panel this morning: A 1" ball base Ram mount to hold a double socket arm that will, in turn, hold an iPad or iPhone on the other end. The mount is held in place by three #10 screws (AN-3-sized) so I installed three #10 nut plates to the back of the panel to allow the mount to be removed if desired.
The mount takes up little room and since it can hold several lengths of double socket arms, it can be used conveniently by either the pilot or the passenger.