Internal memo outlines plans to add more shifts to boost production to pre-lockdown levels even as suppliers struggle to provide parts. Tesla hopes to return production at its Shanghai plant to pre-lockdown levels of 2,600 cars a day by May 16, the company said in an internal memo. Tesla is able to operate only one shift at the plant, but plans to add more shifts in the coming weeks, potentially increasing weekly production to 16,900 vehicles based on Tesla’s established work week at the facility – about the same level as before March lockdowns closed the plant. Tesla declined to…