My information as that The GTA console would run a NAV that had the Intelliag firmware if and I repeat if you could get the Dickey John firmware for  the GTA.  That information was given to me by an Agco employee.  I have questioned DickeyJohn reps at a couple of Farm shows.  They have indicated that getting the needed firmware was not out of the realm of possibility.  But I have not followed up on it.  If you own a combine with the GTA console installed.  This would be the most direct route to get Autopilot on it.

There are many different firmware version for the NAV2.  CNH has their own firmware, Mid-Tech has firmware for their version, Trimble of course has their version and DickeyJohn has a version that I know of.  The different versions are to interface with the different user interface displays.