Another option is TrueCar.
I used to be able to get an X-plan number from my employer up until recently. Now they do TrueCar, and I tried it with my current truck. I was pleasantly surprised how things turned out.
The TrueCar price was reasonable, but I was also able to combine it with a $1250.00 incentive from Ford Credit if I financed a minimum amount with them (took the incentive and paid it off after making 4 payments. Also got a $1000.00 discount for being a Vetran. Actually had to send an image of my DD-214 to prove it.
I was happy with the price, and happy with the trade allowance. I doubt I could have done much better with an X-plan number.
:):)