Going to try to clear some things up based on my history of watching AWP recoveries:
awp generally covers the cars with tarps after they're removed when there are remains inside. Usually because family is on site, or media.
This time they tried their best to cover it as it was surfacing- hence why they started with the back of the car as that emerged first, and then they covered the front also.
If she didn't have a seatbelt on - either because she didn't put it on, or removed it when her car was underwater - then she could have ended up in the backseat or lain across the front seat. Especially since her car flipped upside down and then was turned upright again during the recovery.
The front end damage could be from the vehicle hitting the bottom front first, then flipping on its roof. (Eta: I just saw some clearer images, I was wrong about front end damage - i just see broken side mirror and maybe dent nearby)
Airbags - would they deploy if the impact was underwater and a slow (ish) descent to the bottom? Would the water screw up this mechanism? Would the impact in water be enough to trigger the airbags?
Windows - I've seen that some electric windows don't work after hitting water. They could have been down already, especially if she might have been feeling the effects of substances and that cold breeze could help sober up. IMO. I've done this (as a passenger!). Or the window broke out ?
Inebriation - there seems to be some speculation about even if someone is drunk they won't drive into water. It happens all the time though. It was dark - the moon set around 1230am that night. There's probably no lights, and I've seen on this board that her specific model of car has been known to have pretty dull headlights.
Also *IF* she was drinking up until leaving the party, or *IF* she took substances such as edibles, these can kick in later and you go from being relatively "fine" to completely blitzed
All JMO.
Eta: there are times AWP has recovered vehicles where the driver is in the back seat, no foul play