DC to Baltimore tunnel, LA tunnel network, Chicago airport tunnel. New Roadster, possibly Tesla Semi. Battery swap stations. “Alien dreadnaught” factory with no humans on the production line. Dragon 2 propulsive landing. Self-driving ought to qualify at least partially, because although the project continues and is doing quite well, a huge number of cars were sold with hardware that was promised to be capable of it and turned out not to be.

Wait, is hyperloop not a Musk failure because he never said he would build it, or is it not a failure because his company is still building it? You've said both.