Video answer: How to escape a car sinking in deep water
Top best answers to the question «Why can't you open a car window underwater»
This sounds scary, but you won't be able to open the door until it is fully submerged, because the rising water puts too much pressure against it. Once the pressure inside has equalized the doors should open, though sitting and waiting for this to happen can cause panic.
Video answer: How to escape a submerged vehicle