I remember seeing an actual car that had that problem, but I don't remember what it was. From the windshield post to the seatback was something like 18". In this case a line from the corner of the windshield perpendicular to the door cut line is approx. equal to the wheel diameter, so 20" or less.
Here, from the same link, it is opened up:
The view angle cleverly hides the problem.