Elon Musk has zero clue how public transport works and doesn't seem the least bit interested in figuring it out.

Put a train in there, not one car at a time.

How are these signalled? Are they all "autonomous"? Whatever it is, it sounds like it's ripe for disaster if operating at scale.

Being stuck in a subway train tunnel in a large subway car can be a miserable experience. Being stuck in a tiny pod is undoubtedly worse. It's like being stuck in an elevator you can't stand up in.