I am not sure they will produce 14 M cars, I just stopped doing the math when the 10% of current world market is reached.
While price wise I can see how others call the cars luxury, from a comfort level they are quite different, I would say they add value to mid market cars, function at a performance car level.
Even if their limit were to be 3M, if valued in the market as a growth tech company the potential market cap is good.
Whatever Elon Musk says in terms of production numbers, he does. There is a video where he forecasted to the 100s how many cars they would produce 5 years hence. When he was still driving a gas guzzler. He hit that number on the nose. After that, I never doubted him.
That Indian buffett guy said something similar: if you have someone who 9/10 can hit a hole in one, he's not lucky.