[Responsibility2nd]

Really? Completely submersed? Ugh. I hope and pray I never have to find out. I’d like to think I’d keep cool and not panic, but....

[rightwingextremist1776]

Sure....the pressure builds from the air trying to escape and the water coming in....once everything is where it wants to go (air out, water in) then there is no more pressure keeping the door closed and it will open (provided it isn't locked).

[B4Ranch]

If you get a window open and cannot get out before the water rushing in pushes you back into the car you’ll want to climb into the back seat and be prepared to get your last gasp of air from the the space above the rear window because it can be a long way to the surface.