vintage red matthew wrote:
The chances of the door opening in an accident because it wasn't locked are possible but unlikely. I'm not worried about that much because I always wear a seatbelt. A swinging door might break my arm or an open door might let in something that might cause an injury but again I don't think the door being locked or not will make much difference.
It happens a lot more than you would think.
The door being closed is part of the vehicle structure, it's open and you some loose reinforcement in the part of the car. The door is a very integral part of the body structure.
Example: You can total a Corvette just by opening the door while it's on a lift.
It can crack the frame just behind the door. How do i know, I got screamed at by the service manage that was standing there as I was getting ready to open the door on a Vet that was on the lift. All I heard was a very loud, "STOOOOOOP"!! I was like, What? He pulled up the Service Bulletin and showed me in the owners manual.