Sparrow racing should go a little like this. You find a somebody braging about how they're the best at destiny so you challenge them to race Sparrows. They accept. The perrson challenged chooses a planet (full game), the game then puts random checkpoints in a line around the map to a random location. You race and the winner gets a reward and respect (new system of leveling for increased Sparrow handling to perform quicker turns, or new maneuvers), the loser gets nothing. You could also wager items from your inventory or vault. Raceds could be makeshift or created by player or computer.. For big races they could be planned ahead of time and by players. Players in explore mode would not no it is happening unless they saw it announced. the player would see two or more Sparrows racing straight at them not knowin whats happening.