ford performance tune

Does anyone know if a list of certified ford performance tuners exist? I called 3 ford dealers near me (suburbs near Chicago) all of which dont know anything about the tune or installing it. For those that's done the tune did you just call around till someone said they do it? This is the one...

A few days ago, I put my 2016 ecoboost mustang in reverse and it started to violently vibrate. I knew I could not drive it so put it back in park and the vibration stopped. I put it back in reverse and everything was fine. Now 2 days later, same exact thing happened. Each time, so far, this...