So if you plan with RWGPS then it looks pretty simple - you could plot on the fly, on the phone, then the route is shared with the head unit and you can follow it (if I'm reading this correctly).
You've still got two points of failure with the REFLKT. Their self-contained unit is of more interest to me. I'd like to save phones power for backup/emergency use. I'm not sure what the Bluetooth on all the time does to my battery life.
So if you plan with RWGPS then it looks pretty simple - you could plot on the fly, on the phone, then the route is shared with the head unit and you can follow it (if I'm reading this correctly).