A long, long time ago -- in the days before cell phones -- I was driving home through the city late one night and stopped at a traffic light. A woman who was either drunk or on drugs came up to my passenger door and tried to open it. Mercifully, I had locked it -- that didn't stop her from continuing to try. She was babbling about something but I couldn't figure out what. I drove a couple of blocks up the street, stopped at an all-night gas station, and used their phone to call the cops.
I wasn't afraid for me safety, but if she had gotten into my car I don't know how I ever would have gotten her out. The biggest reason I called the cops was that I was afraid she'd get hit by someone because she was wandering around in the travel portion of the street.
Yeah, ALWAYS lock the doors.