I am being realistic. Your auto with 3:55 is probably quick as hell in a straight line. You should be able to beat a PP GT 9 out of 10 times in a straight line. It probably handles pretty good through the turns. A Performance Package GT with a beefed up suspension, Brembos, and 3:73 gears is made for road courses and tracks and handles great through the turns. A competent driver will leave you and your auto behind. Being able to press a pedal to the floor and going fast doesn't equate to being a good road course driver.
If you notice, they don't sell the performance package in auto. There is a reason for that. They don't sell the GT350 in auto. There is a reason for that. Even the Focus RS only comes in manual. The auto is definitely the future but we are talking now. And right now, in a Ford Mustang, the manual is better for a road course or track. Period.
2018 Lightning Blue GT Premium; Performance Package 1:
MagneRide; Active Exhaust