Sparrow races with different tiers of competition with progressively trickier maps. Sprint races, circuit races, points/tricks competitions. With many different sparrows to unlock/upgrade. A whole new Tower Faction with it's own Rep and purchases available including race gear, sparrows, and upgrades. I think this would be amazing and it would allow gamers a whole new way to experience Destiny; racing crazy rocket powered hover-bikes around some of the solar system's most insane settings.