Tesla CEO Elon Musk recently spoke to Fox Business about the state of Model S production, and to hear the CEO tell it, things are going very well. Assembly line production has been climbing every week; the interview was conducted on September 13, and Musk said when asked how many cars they'd build, "I think it's probably going to be around 80 cars this week." If they hit that number it would represent double the production of the week before.
Tesla's Model S production goal this year is 5,000 units, and the outside estimate is that
*UPDATE: Tesla spokeswoman Christina Ra pointed out that the last publicly confirmed number is just 100 Model S units, and that Tesla will "likely make another announcement on that front soon." She added, "400 is really inaccurate."