But partially submerged when 20% of the door is still above water then yes it should be possible to still open the door
Partially submerged, the door would be very hard to open, due to water pressure. The water pressure needs to fully equalized between the inside and outside of the car.
Did we learn nothing from Mythbusters?
Yeah, take Jeremy Soule, for example. He's talented, experienced, and composing all of these broad symphonic soundtracks for Elder Scrolls, Skyrim, and Harry Potter games.
But, what's the soundtrack of his that sticks out in my mind? Secret of Evermore. Underrated as fuck soundtrack for an underrated as fuck game. Back when he was forced to compose for a game with limited hardware and instrumentation, where he had to use distinct melodies to achieve a sound that sticks in everybody's minds.
Every Frame a Painting did a good video on this subject, as it pertains to the Marvel movies.