RTZ, This summer Tesla opened a second assembly line, but it has been slower to get sped up than desired. I'm told that two shifts are working at present. During the 3rd Quarter earnings report, Elon Musk identified the need to speed up production while maintaining quality as the biggest challenge before Tesla at this point. Rest assured that Tesla is working furiously to get as many cars completed this quarter as possible, AS LONG AS THE QUALITY IS STILL THERE. Earlier this summer the production line was turning out 800 cars per week, we've heard confirmation of 1,000 cars per week, and I'm hoping the factory is now up to 1200 cars per week. One of the lines is using innovative new approaches, and speeding up such new equipment takes serious tweaking. If you live close to California, take a factory tour and you'll get the picture.
The second assembly line, also called the "high speed line" is designed to build S and X. The old line was somewhat taken apart for equipment for the new line. That is one reason they cannot run the two lines together. This was told to me by someone working on setting up the new line. Some presentations say the old line can be used for prototypes and betas or whatever - however, I do not think the old line is possible to be used now. The new line is supposed to be able to do up to 400 per day at full capacity (3 shifts).