One by one, Tesla Model Y Ls roll out of the company’s end-of-line inspection bays, gleaming in black, white and gold. They are a mix of left-hand and right-hand drive – one of many signs the electric vehicles (EVs) produced here are destined for ports around the world. The company touts a total assembly time of less than 40 seconds at its sprawling Gigafactory in Lingang, a coastal area on the far southeastern edge of Shanghai. From there, Tesla says, a finished car can reach the port and be...