I remember the events as they took place. I’ve always wondered why she couldn’t get out. Most vehicles back then had manual windows. Just wondering..........
The 67/68 Olds Delmont 88 had power windows.
So it is logical to surmise that Mary Jo got banged around. She was also drunk. Injured to some degree, disoriented, stunned and drunk, she wasn't thinking clearly and just went to the air pocket, probably thinking Kennedy would get rescuers. To me this is the most reasonable "innocent" explanation.
A non-innocent explanation is that she was already in the back seat, possibly unconscious either from drink or a blow from Kennedy. She wakes up in the back of an overturned car, not thinking clearly, so she waits for rescue. He might have pushed the car over. It is so close to the bridge that it could not have been traveling very fast or its momentum would have carried it further out away from the bridge. So I have always harbored the suspicion that she was murdered; that it was not an accident. Rumors swirled that she was pregnant. Whatever the truth, at minimum Kennedy got away with negligent homicide.