In the first place, how are you perceiving a threat? At sixty mph or more, anyone who can open the door or climb in the window can have my car as a gift. In traffic, the doors are locked, the windows are up, how does someone outside present a threat? The only time this has happened to me, an escaped prisoner in Orange California ran into the street and demanded my car as I sat at a blvd. stop sign. I opened the door, (old VW bug) and stepped carefully out of the way so he could get in the car. When he began lowering himself into the seat, I slammed the door on his head, grabbed a handful of hair and jerked him prone face down on the street and THEN and only then pulled my CCW and jammed it in his ear. A few seconds later I was joined by the City of Orange Californias' finest and the heart rate started back down to normal. In reviewing all my choices, window down, knife in his hand, I am sure to this day that I did the right thing. I got out of my cage to where I could move around, waited for the opportunity to inflict instant and severe trauma to the perp and then neutralized him. Had I gone for my gun in that VW I probably would have been cut badly and might even have lost my weapon to the bg.