Just like A/GAS, these three gas classes are indexed classes for full bodied or “door cars”. An index is a set number that the cars cannot run quicker than. If a car runs under the index during qualifying – that competitor is placed at the bottom of the qualifying order. If a car runs under the index during eliminations, the driver loses to the car that ran over the index. If both cars run under the index during the race, the car that runs closest to the index number is declared the winner of the race.