17 cars on a 7×8 lot. 50 seconds on the clock.
17 cars left
You have 50 seconds, starting at your first tap. A bump costs 3 seconds.
Drive the cars out in this order: 3, 2, 1, 4, 5, 6, 8, 7, 9, 10, 13, 12, 11, 15, 14, 16, 17.