[mikeash]

Note that Tesla's goal isn't 500,000 cars in 2018, but rather a production rate of 500,000/year by the end of 2018. In other words, they're aiming for ~10,000 cars in the last week of December, and probably less before that.

This is easier than actually producing 500,000 cars in 2018, of course, so that just makes it all the more likely they'll get there. Will be really interesting to see how they fare in the next two years or so.

[Robotbeat]

Assuming they meet 20,000/month in December 2017 as Musk says and ~40,000/month in December 2018 as you say, then linearly extrapolating between the two would still get you about 350-400k per year. Same order of magnitude.

[grecy]

And it seems likely if they can achieve 20,000/month in December 2017 they will be able to double that in 12 months.

I would expect them to double it faster, actually.