If you dent a car in the parking lot, leave a note with your real number. That note is the whole test.

Denting a car in an empty lot is the cleanest honesty test available, because getting away with it is guaranteed. There is no witness, no camera and no consequence coming, which means the note has nothing to do with avoiding trouble. It is about whether you accept the cost of something you did when nobody is making you.

Keep a pen in the car so the decision never comes down to logistics. Write your name, your number and what happened, and put it where it will not blow away. If you cannot bring yourself to write it, that is worth knowing, and the choice is still there tomorrow.