The point of this is that Musk has a tendency to... um.. exaggerate the capabilities of his misleading named safety enhancement feature to the level of dangerous fraud.
Even I would have thought that custom programming (if necessary) the dumb car to travel down a tunnel all by itself would have been easier than rigging it some tacked on extra alignment wheels. I get that driving in the real world is complicated, but how can you not be able to program the system with complete accuracy and maybe just some extra sensors?
So bizarre.