The only "show specials" I've seen are the units they actually put on the floor and had tons of people tromp thru it and then sell it to you when it's all done.. ;)
Sure, I've seen the ones that they lock the door on and it says "SOLD" on it... Great.. If it's what you want and the $$ you want to spend, there is no problem with that.. You can get a great deal that way IMO..
But, if you expect to go to a show and special order a rig and pick it up months later... Well, you might get a benefit from talking to the guy on floor, if he really does work for the dealership.. Or maybe you just get the same thing that you would get dropping in on them on a Wednesday??
I've never bought from a 'show', but I sure found out what I like and don't like about a rig and the dealership involved..
Good luck!
Mitch