One that can't be used on public roads or in public. What sort of fucking genius inventor invents something that can't be used, rendering it utterly fucking pointless?
But you do know that these funny things called fighter jets have already been invented don't you? You know, ones that can already do the things that Elon the great's 'invention' can do?
Once again, Elon the fantastic proves he's not actually an innovator, just good at copying. Maybe he should have been Chinese?