It has always been clear that Musk does not understand high-volume manufacturing. Building rockets is very hard, but building 100,000 cars is very hard for a different reason! His predicted ramp rate was absurd. In the last 6 months, I think he has started to realize this.

Tesla has little chance of hitting its 5,000 weekly output during the fourth quarter. The chief reason: Its current production line can’t build vehicles at that rate unless it runs two 10-hour shifts seven days a week, which is unlikely. impossible.

Source: Tesla | Hiccups Threaten to Slow Model 3 Launch | Industry content from WardsAuto

According to the article, Tesla has also deliberately ignored much of the accumulated wisdom about how to ramp in auto production. That might be OK for his second high-volume vehicle.

More details on Tesla’s ramp plans:

Manufacturing expert says Tesla Model 3 plan to skip beta testing is risky

Tesla now has 2 choices, both bad:

1. Go ahead and start building and shipping as fast as possible. The result will be multiple problems that require expensive hardware recalls.
2. Add another 6? months to the schedule to run the as a pilot line for learning, rather than for volume. Expect zero salable output during that period. (As one of the comments said, they can give/sell those cars to employees.)

Added December 27: Tesla “still in manufacturing hell.”

Latest of many articles about Tesla manufacturing problems.

Here is a comment on that article: Musk  needs to face up to having made a MAJOR mistake when he skipped some steps in the original manufacturing ramp-up.
He is probably also making another major mistake at present: adding new machines to the manufacturing process, before he has the existing machines working perfectly. This seems logical to people with no manufacturing experience, but it does not work. For one thing, it diverts his key resource, which right now is manufacturing engineers.