The Rolex 24 is my favorite endurance race of the year, and this is effectively the beginning of the Daytona weekend. The SportCar challenge has always been about learning multi-class racing, and the introduction of the new GT3-spec GTDX class in between the GT4-based GSX and the top-class LMP3s only adds to that goal. Let's take a look at how the first major event in American motorsports shaped up.