Question:

If you collide with an unattended vehicle, what must you do?

A Leave a detailed note with contact information in an obvious location.

Explaination

If you collide with an unattended vehicle and the vehicle's driver cannot be easily located, you are legally required to leave a detailed note on an obvious place on the vehicle. The note must include enough information for the other driver to be able to contact you or notify his or her insurer about you. [A. Crashes, Section 8: Crashes and Traffic Stops, Maryland Driver's Manual]