Lance,

I just read your post a little closer.  From my understading, the cart tractor, when used in this particular mode will actually talk to the combines globe, therefore track off the same math...

this is (i think) Deeres first step towards creating multiple cover maps on a single display - the ability to have globes communicate and operate off each other.  You got two combines in the same field, and both coverage maps will show on each others displays...

i never saw this stuff personally, but when I was an AMS guy with a Deere dealership we caught wind of what was up and coming...