Been instructed that here in Texas on big trucks that GPS receivers must be mounted outside of the windshield wiper sweep and no more than six inches from glass frame. My CB is within this range. Some drivers I know keep the GPS next to CB. On the latest truck I'll try to mount to a board to hang from near roof. Still close enough to manipulate, but completely off of view through glass.
I use both a beanbag mount and a separate articulated arm to mount my 7" Garmin so that it drapes down over the dash on my Peterbilt. The top of it is, in my line of sight, just below the front edge of the hood. Even then I've had personnel at state scales come out to view whether or not my view is obstructed.
I use it in my pickup the sane way. I also use a tablet holder for the iPhone that suction cup mounts along side the A-pillar. Sits on the dash edge at the door, roughly. As I sit quite high, it works well.
I'd say be willing to spend on mounts. I have $80 in the first mount and $40 in the second.