Final answer:
When causing property damage to a parked car and the owner is absent, it's required by law to leave a note with contact information and, in significant cases, call the police.
Step-by-step explanation:
If you cause property damage to a parked car or object and cannot locate its owner, the correct course of action is to leave a note with your contact information. This is not only the responsible and ethical thing to do, but it is usually required by law. If the damage is significant, you should also call the police and report the incident. Ignoring the situation or failing to pay for the damages can have legal repercussions. Providing your contact information and notifying law enforcement ensures that you're taking the necessary steps to address the incident properly.