Answer:
Tom has apparently been promising to sell his car to George Wilson for some time. George owns a garage in the valley of ashes, the economically depressed area that exists between New York City and the Eggs (East and West, where the Buchanans and Nick live, respectively). When Tom and Nick arrive at the garage in Chapter Two, "a damp gleam of hope sprang into [George's] light blue eyes." He is clearly hopeful that Tom has come by in order to discuss this sale, but Tom delays, saying that he can't bring the car until next week. Poor George hopes for a financial boon, something on which he can make a bit of money (as the Wilsons are clearly not well-to-do people), when Tom has actually shown up in order to tell George's wife, Myrtle, Tom's mistress, to leave now and meet him in the city.