I think what he means is "What if you're in a car that is not yours?", e.g., you've borrowed someone else's car or you're in a rental car.

Given that scenario (I've been in an auto accident, and I'm injured)...
Unless there's an urgent need to get out of the vehicle (i.e., it's sinking in a pond or is on fire), assuming I can move at all, the first tool I'd reach for is my mobile phone or ham radio to call for help. Then I'd just sit there until someone came. The "don't move an injured person unless absolutely neccesary" rule still applies even when the injury is to you.

Dave F>