Right when you start, but the 1st car that pops up. If you have enough points to buy a second car, Don't do it right at that second. Wait for a couple more races, then you should buy the Zellion. Then if you have enough for a 3rd car... DON'T BUY IT! you only need 2 from every 4 of the categories. (Roadster, Sport car,etc.) (If you have 2 cars, you'll be getting at lest half more cars sold than you did with 1!)