Most dealers can install heated seats I believe. If not most then the one I purchased from in marietta GA (Team Ford). My sister purchased a mustang from the same dealer as I did and she asked that hers be equipped with heated seats. I do not believe they charged her anymore than they would cost as an upgrade on any other car. I havent been home to visit her since just after she got the car, but I think they mounted the switch for them below the HVAC controls near the defrost button in one of the "dead" button spots.
In any case my point is that many of Fords large dealerships can add options like this. Her car also was equipped with those back up warning things that beep inside the car when you back close to something. I dont know if this was because she requested that also or if the dealer did that or if it is simply an option.
You guys get the point.