I spent some time working on this today.  Since the tractor is a Tier 4b and the NAVII is outside the rear of the cab I think I'll be able to put the TM200 behind the rear panel inside the cab.  There's a lot of wiring to stuff in there but I think it will work.  I'll try to update once I get it put together.  I have on more harness for the cameras to get from my dealer yet.