airbag will open, etc, so when you realize you are in trouble, the car is already underwater,
and you can only open the doors when the pressure is equalized (and you will be dead then anyway).
Yes, if you can open the door instantly like Hammond, you will survive, but in real situations,
it just not possible, because of the shock. Not to mention your injuries after the crash,
and the car will deform so much, that you can't open the doors.