SVTFreak, as I said this was how it went in 2007 and its possible things have changed. when I worked at the dealer we were told all dealers participate in x-plan and it would be counter-productive as you sent a sale to someone else. Remember this was at the time things were getting desperate but...
I haven't heard of a dealer which hasn't honored X Plan, and if they are then they are breaking their dealer franchise agreement with FoMoCo. It's a really easy and simple process, if it hasn't changed since I worked at FoMoCo last in 2007. Basically you have to contact your X-plan...