 Index of Effluency is the top prize awarded in a series of endurance races that  holds the Guinness World Record for what?
Index of Effluency: Index of Effluency (or IOE) is the top prize awarded in the 24 Hours of LeMons automotive racing series. 24 Hours of LeMons:  The series holds the Guinness World Record for the "Most participants in one race" (216 cars).
i don't know