'Our Model 3 production plan includes periods of planned downtime in both Fremont and Gigafactory 1,' a Tesla spokesperson told Reuters in an email. 'These periods are used to improve automation and systematically address bottlenecks in order to increase production rates.' The Tesla Model S Fremont, where the Teslas are built, is near San Jose, California. Their batteries are manufactured at the Gigafactory 1 in Sparks, near Reno, Nevada. The company did not provide specifics about the production upgrade, but it said there could be more periods of downtime in coming months. In the fourth quarter, Tesla said it delivered 28,425 Model S and Model X vehicles and 1,542 Model 3 vehicles, totalling 29,967 deliveries. Tesla's full statement: 'Our goal is to produce perfect cars for every customer. That is why we review every vehicle for even the smallest refinement and conduct extensive end of line quality checks before a customer takes delivery of their car.