Just FYI....
CoPilot GPS. $24.95 max on the istore, less on android.
Has RV / truck mode.
Has all ondevice mapping, internet connection not required to use it.
Full turn by turn directions.
On device POI's less than ideal, google search available if you have an internet connection, that is less than ideal too. Mostly you get hits to nearby state farm insurance offices... lol.
Still WAY better than a $500 does nothing else ever hardware solution.
I put my iPad mini in a Bluetooth "keyboard case" and vecroed it to the steering wheel... nuf said.