[semi-extrinsic]

It's worth noting, though, that for the Model S and X the assembly lines were not built by Tesla. The Model 3 assembly line is the first one Tesla's ever made themselves.

The "old" Tesla factory was bought from a joint GM-Toyota venture that achieved average production of 25 000 vehicles per month running those lines for 25 years. Then that venture failed, Tesla bought the factory and repurposed the existing infrastructure.

It's like if SpaceX started by buying an old working NASA rocket design and repurposed it for the Falcon, but for Falcon Heavy they started entirely from scratch developing rocket fuels, engines, materials etc. without ever having done so before.

[sgc]

It's not really like that at all. To begin with, a Roadster / model S is not a repurposed Toyota - and that is exactly why Tesla has succeeded so far. Further, they completely reworked those lines with a huge amount of new equipment, to the point that is was worth it to them to buy the robotics manufacturer. It is closer to a technicality than starting from scratch. And as far as anyone knows, a huge part of the bottleneck hasn't even been in Fremont, but at the gigafactory (which they also built prior to the 3) - with a supplier who they have since removed from the equation.