I think Elon Musk is a bit of a fraud. He just pre-announces things that he can't supply now and then waits (and hopes) for technology to catch up - that is basically the trucks. His self-driving cars seem prone to bursting into flames when they are not driving themselves into the backs of trucks, the technology is not as advanced or polished as he makes out.
Also, it's also not like he's developed all the space stuff himself - all the real hard work and risk was done by the US government over many decades figuring out all the minutia of going into space when everything was unknown and now he profits from it to make it commercial. Nothing that other groups weren't already doing anyway.
Apparently, he can't figure out how to mass-produce cars. Something Henry Ford managed with far less technology a long, long time ago.