I remember in their press letter that said they have the capacity to produce 500k cars this year.
There are a couple different things. In terms of the number 500,000, the Q2 letter said installed capacity at Fremont for 3/Y was going from 400k to 500k. Which means at the end of the year, the plant has the ability to make 500k a year, not that it would make 500k in 2020.
It also showed 690k total current global production capacity for all models and factories. The first half had 185k production, requiring 315k more or a yearly capacity of 630k, so 500k was possible. Q3 added 145k, so we need 170k more or a 680k annual rate.
https://tesla-cdn.thron.com/static/DK2EWG_TSLA_Update_Letter_2020-2Q_G6S6GG.pdf
Although the Model Y production line was operating for about four months in the first half of 2020 due to shutdowns, we exited Q2 with Model Y production running at installed capacity. This ramp was significantly faster than our initial Model 3 ramp, which took over nine months to reach the same weekly rate. We are installing additional machinery at the Fremont Factory, which is expected to increase total Model 3 / Model Y capacity from 400,000 to 500,000 units per year.