Take your SHO to a CarMax? I'd hope they give you at least $18K. I'd want $20K minimum, but might be a dream.
2011 to a 2014 would be a good upgrade. LED tails, new grille, remote start, MyFordTouch, heated steering wheel, power steering wheel, new gauge cluster, new steering wheel, etc etc. If you get another PP, 2013+ PP gets more goodies.