Found mine at a Ford dealer outside of Dallas on auto trader, had it listed for $17,5k was $4-5k off sticker price, '16 model in Magnetic, no sunroof, no nav, no Recaro.
I got a great trade number from the dealer on my '15 Mustang GT which also kept me from paying sales tax as the Mustang was worth more than what I was buying. I got 0% for 72 months through Ford Credit and I never had to step foot in the dealer. They delivered my new car and paperwork and took the Mustang back with them, easiest car deal I've ever done.