Your post took me back to the OP and I had thoughts along the lines of what was the cause of death in those recoveries... Were they conscious long enough to get out but just couldn’t egress; were they unconscious after making contact with the water at very high speed; or did the victims die on impact with the water? You have to be conscious and physically able to egress or spare air can only delay the inevitable.

IMO focus here should be on egress, getting physically clear of the car/truck.