Since I went through the 'process' in my recent inquiry into a new car purchase for a '15, I dealt online and face time at the dealership. I dealt with 3 dealerships in the process, settling on the dealer that I bought my current Mustang from. We worked together online and in person. I got the best trade in value from this dealer which left doing the deal on the car that I would have to order.
That's where things got sticky. The only way I could get them to budge off of sticker is to use x plan pricing. I didn't think it was a good enough deal because they seemed to have no compromise in the price so, I decided I would not deal at this time. If a dealer can't budge on price, they aren't dealing in my view. They want to get maximum profit.
Also, I have to take exception to how many Mustangs are getting sold on average. With the cars that are on the lots here and since I stopped shopping almost a month ago, one Mustang has been sold at the dealership I was dealing with and none at the other dealers in the area. One of things I pay attention to, when I'm looking at the sticker price of the car, I also look at the date the car was shipped. Most of the Mustangs at all the dealerships were delivered last year with only a few shipped in January. When I see this, it says a lot.