Just a thought: making cars comfortable and safe for the drivers also makes them weigh A LOT. Which makes for huge emissions. If we were to consider ecology, taking a 70kg individual somewhere shouldn't be by a 2000kg vehicle.

As a pedestrian/cyclist/driver I'd love to see cars that are basically motorized tents weighing something like 100kg. That would make me feel much safer when outside the car, and much more considerate of others while inside.