call around. Tampa/Orlando area has a few big dealers and those are reasonably likely to do AZXD plan. Otherwise buy from VA/MD area and take the AutoTrain from Lorton VA to Orlando. If you can't bring yourself to drive all the neat roads from Front Royal VA all the way down the Appalachian Trail.
I got mine at Palm Coast. Emailed and said I had the x plan, what was the out the door price they could give me on the one they had in stock. They were very quick and answered the questions exactly as I expected. (none of this, what color do you like, when I put YELLOW in the email!) Call Palm Coast and ask if you can order with an x plan and they should be able to take care of you.
Mullinax in New Smyrna (and all around Orlando) was very straight forward too but they didn't have yellow. FYI Coggin in Jacksonville just tried to upsell me something on their lot that I didn't want from the start.
the biggest advantage to having an X plan number from say Mustang Club of America (costs $35 for membership, you have to wait 90 days to get a X plan number) isn't the savings on the car, it really isn't a lot of money and if you know what the dealer cost of options and packages are toy can figure it out in five minutes (one of the members used to post the ordering guide info with dealer pricing. It is dealer cost less point four percent, plus full cost on shipping
The big savings especially in Florida where they bend you over like a new prisoner in the state prison and screw you on the "doc" fees, the X plan puts a severe limit on what the dealer can charge you for that, IIRC it is something like $100 but I have seen stuff that says it is as high as $300, but I have not verified that higher number.
I know in 6/24 when I bought mine it was $75
There is supposed to be a $275 fee for using X plan but my dealer didn't hit me with that.