20 cars on a 7×9 lot. 55 seconds on the clock.
20 cars left
You have 55 seconds, starting at your first tap. A bump costs 3 seconds.
Drive the cars out in this order: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 13, 15, 17, 16, 20, 19, 18.