The S650 Ford Mustang has just debuted, and while it has many new features that take the iconic pony car into the future, some are more fun than others. People can gawk at the 13.2-inch SYNC 4 center stack and real-time graphical renderings. But the real fun is had behind the wheel, which is where the new drift stick comes into play. Since electronic brakes have been integrated into cars, we’ve lost the ability to lock up the rear wheels and fling a car’s tail to and fro in a safe open space, but that’s no longer the case with the S650 Ford Mustang. Thanks to a segment-first electronic drift b…