21 cars on a 7×9 lot. 65 seconds on the clock.
21 cars left
You have 65 seconds, starting at your first tap. A bump costs 3 seconds.
Drive the cars out in this order: 2, 3, 5, 9, 10, 12, 13, 16, 17, 19, 18, 20, 21, 8, 15, 14, 1, 4, 7, 6, 11.