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: 1, 2, 4, 3, 7, 10, 14, 9, 15, 6, 16, 17, 11, 5, 8, 12, 13.