On the topic of valuing Tesla against other car companies, here's why I think Tesla could easily be worth more than all other car companies combined.
1. Tesla owns all service and sales locations. Other carmakers do not.
2. Tesla has its own proprietary driving autonomy solution which is all in-house, comes in a package that is affordable (low hardware cost) and already deployed. The only thing holding it back is software. Recall the valuation of Mobileye when it was purchased, which is not as complete a deployed solution. Any carmaker that wants to use Mobileye will have to pay a good chunk of cash to Mobileye. Tesla keeps all of theirs.
3. Related to (2), Tesla is the only carmaker with a well-developed software deployment strategy. This is a huge benefit.
4. Tesla has a huge technical, production, and market share lead in the up-and-coming drivetrain technology (EVs), whereas everyone else has the *liability* of the outgoing drivetrain technology (ICE). Again, it is a liability to be focused on a dying technology. Tesla has zero of this liability.
5. Is there any carmaker that is more vertically integrated than Tesla? I don't think so. Result? Higher margins because Tesla keeps more of the pie.
6. Tesla's vehicle margins are far above the industry average. They can make the same amount of money by selling far less cars.
7. Tesla owns the refueling locations (Superchargers) and has refueling infrastructure far beyond anyone else.
8. Tesla has a huge lead in battery production capacity. Nobody else comes close.
9. Tesla is not just a carmaker. They are also a major provider of energy storage, a market which is growing quickly.
10. Tesla solar. Yet another industry.
11. Tesla is also going into the short and long-haul trucking industry, something most carmakers do not dabble in.
12. Tesla collects far more autonomous driving data than anyone else. Not even close. Data is valuable with AI, because data is king.
13. Tesla has the most tenured CEO, someone who is known for his tenacity and for succeeding at doing things previously thought nearly impossible. (Rockets landing without going boom).
14. The best engineers in the world want to work at Tesla. The best engineers in the world don't want to work at GM.
15. Tesla is securing tons of battery supply, or seeking ways to vertically integrate battery production. Again, cut out the middleman, starve others from battery supply, etc. Helps cement your lead.
16. Tesla has strong brand recognition as a leader in EV technology and customer satisfaction.
17. Tesla is a proven innovator, over and over again. This is valuable.
I'm sure there are more reasons. This is just what I thought up over the course of 5-10 minutes.