High-stakes bidding on million-dollar race cars. Frantic bets placed in secret even as the cars race around the track. And to the victor, the biggest purse of all. But in the world of motor racing, the margin between victory and defeat can be a single moment: a steep banked turn, tires screaming and spitting out smoke, and the downforce, pressing you down in your seat and keeping you on the track as you make your move inside to pull ahead.