I have been taking my cars to PD for a long time. They are all great guys, and Dan really knows how to tune a stang!
They are remodeling their shop now to add a couple more lifts so that they can handle more customers.. they are ALWAYS busy.
My tuner told me when I was running E85 "It makes spark knock a non-issue" because the octane rating is so high. That being said, I had to stop using it because I couldn't get it anywhere near the tracks that I go to :(