Read through accounts of sightings of strange beasts, ghosts, UFOs. If you took out all the ones which began 'I was driving late at night when...' there'd be few left.. Then if you took out all the ones which began 'I woke up in the middle of the night and...' the list would be greatly depleted.
IOW - I'm not even being sceptical. The mind goes into a strange state, who knows what that means. Perhaps it opens the doors of perception. Perhaps it weakens the membrane between conscious and subconscious. Just driving.