I posted what Steve ODonnell said they were looking at and building a test mule for short tracks and probably road courses and they are going to be testing at Richmond with it. They are going to be looking at aero, tires, possibly brakes and eliminating shifting. They had to shave a lot of weight from the LeMans car and he mentioned the underbody tray removal/modification and other cheap aero improvements that I read would make the car even faster. These aren't going to be expensive changes like raising horsepower which is ridiculously expensive to do. It's all in the clip below, straight from the horses mouth.