The reason mine is up past the seat is so if the door became locked/smashed shut I can get to the bottle still. I tested it in a few positions with the door closed and me in the seat with my belt on.
That's a very good point. I thought about mounting mine further forward, but ultimately decided not to because my big *** feet would constantly hit it getting in and out of the car. Also, my floor pan is really irregular in that area and where I mounted it is relatively level.