Zero Chance, I beg to differ with the Ford bulliten that you mentioned. It's simply not true. I have done it both ways, repeatedly. (I'm not the only one that works with and to my knowledge, there are no "plates in my head".)
I can stand at the edge of the range with the remote held ABOVE MY HEAD, move back 20 feet and not have the car respond. When I LOWER the remote and touch it to my chin, the car responds by doing the command of the button that is pushed. When someone else tries it, it works exactly the same.
Car alarm manufacturers have put it in their instruction manuals to try this method, if the alarm does not respond. (I have a buddy that installs car alarms and the like, for a living.)