Tesla is extending its lead and advantages over other car makers. Tesla is leading with batteries and is adding other design, technology (less wiring, better batteries) and other advantages. Tesla also does not have to spend on advertising to sell out all of the cars they are building.
Tesla China clearly benefited from the lower labor costs and vast construction capabilities in China. However, they also have made design improvements in the car, improved the factory design and improved the machines used in their factory.
The body of the Model 3 can be stamped in one part instead of 75 parts.
The wiring has been reduced from 3000 meters in the Model S to 1500 meters in the Model 3 and will be 100 meters in the Model Y.
It will be interesting to see what the factory efficiency and costs will be for the German Gigafactory and the next US Gigafactory. They will not have the lower China labor costs but they will have continued improvement in vehicle, factory and production equipment. In particular, the Maxwell Technology battery innovations will only need 6% of the factory space for the equivalent level of battery production.