"Robby, why don't we just take one?" After a long delay sitting on a tarmac leaving Kentucky for the Timonium 2-year-old sale, Stuart Angus and I arrived to find an understaffed rental car counter, with a line that appeared to be hours long. He figured we could short-circuit the process by getting in a car and bluffing our way through the gate agent. It nearly worked; the agent's hand hovered over the button to raise the gate, before she said, "Oh, you need a rental agreement, not just a reservation."...