I believe Tesla cars are better suited for four-wheel steering than any other ICE car in history that has attempted four-wheel steering. With Tesla cars, engineers have greater freedom on how to design the actuators and the software to enable the rear wheels to have a digitally-controlled adjustable steering radius. Imagine the possibilities of four-wheel steering with Autopilot. Self-parking algorithms can be improved with an additional variable of a rear steering angle complementing the front steering angle. High-speed maneuvers and low-speed maneuvers can be completely changed. Look at this video of the A* search algorithm that is based on a fixed straight-angle for the rear wheels - http://blog.habrador.com/2015/11/explaining-hybrid-star-pathfinding.html
- and imagine how the maneuvers can improve with an adjustable rear radius. Translational movement in addition to tighter rotational movement can be made possible.