Taking a lead from the Rule of Threes, what could challenge your ability to breathe and what in the vehicle could help you meet that challenge?

Perhaps a smothering, particulate- or ash-laden, cloud or other airborne breathing threat? Using the engine air filter, heating-air conditioning hoses, and seat coverings and insulation you have a shot at creating a breathing mask system defending your airway and lungs.

Perhaps invading water, or a need to use a waterway to survive, brings drowning into the picture? Air-filled tires and foam seat-filling both float, and ropes of scavenged wire-harness twisted or braided together could lash them together. Some of the smaller fill or overflow tanks, such as those for coolant or windshield washers, might be scavenged and sealed with seat foam plugs to add buoyancy.