15 cars on a 7×8 lot. 45 seconds on the clock.
15 cars left
You have 45 seconds, starting at your first tap. A bump costs 3 seconds.
Drive the cars out in this order: 1, 6, 11, 5, 7, 12, 13, 8, 14, 2, 15, 10, 9, 3, 4.