It is obvious to anybody looking at the balance sheets of the company that TSLA will need to raise capital soon. Either late 2018 or maybe early 2019. A company with $3 Billion cash that's losing $1-billion per quarter will need more money. That's just the facts.
Musk is going to be either relying upon institutional investors / the stock market in general for another round of equity offerings, or relying upon banks for a loan. In either case, it seems like Musk just bit the hand that feeds his company money.
Another 300,000 reservations at $1000 per is probably not going to happen. There are fewer and fewer ways for TSLA to raise tons of money.
I'm not necessarily saying "TSLA Will definitely run out of money in 3-quarters". I'm saying "TSLA is currently, on a linear-approximation track to run out of money in 3-quarters".
Obviously, the Model 3 rampup will improve profitability. But the Model 3 Ramp-up also requires more resources (more humans in the assembly line. More robots in the assembly line. etc. etc.). So that still requires money.
A linear approximation is basically a quick-but-shitty-approximation. Its really easy to calculate and full of flaws, but full of flaws in a way that almost everyone can immediately understand.
Exponential approximations (ie: Musk's approach) might be more realistic... since production lines can exponentially grow to some degree. But if you are off by even a little bit, then you end up being ... oh I dunno... 8-months to 10 months late with your 5000-cars per-week estimate.