I was out with a Shelby club not long ago and ended up following a black Shelby around the track for awhile. It was pretty well matched. I think he was ever so slightly faster on the straights, but I was beating him in the corners. I could get on the throttle earlier and was out braking him. Eventually I got the point by. No idea what he was running. I went to talk to him after the session and he drove off as I was walking up. Mine was on PSS and only mod was camber plates since M4s aren't adjustable from the factory.