While the risk of disappointment is real, I want to clarify the issue of InsideEV's estimates. I believe they subscribe to data from a number of feeds that get their data from the limited number of states that provide such data. They then adjust that number for a variety of factors, including a gut based guess. They also correct those numbers over the course of a year to then line things up. So the intra-quarter numbers are a reasonable guess, but certainly not strictly accurate, as opposed to many of the European numbers, with the caveat that deliveries != registrations even there.
In a normal quarter, the variance in delivery times range from same day at the Fremont factory, a few days on the west coast, a week or so for trucking in many parts of the U.S., 3 weeks if they use rail+truck, to 8-15 weeks for deliveries overseas like to China or the UK. The UK, for instance, often has vehicles in major parts trucked across the U.S., boards a ship for the Netherlands, gets re-assembled, then shipped to the UK and trucked to the delivery location. That can be across most of a quarter... 10+ weeks. So, Tesla has always done geographical batching with overseas deliveries primarily at the beginning of a quarter and shifting emphasis to domestic and then west coast and then California deliveries. They then also start up making vehicles for overseas at the very, very end when they have built out the California orders for the quarter.
In Q4, the factory was cutting over to AP2 and was shut down for some part of the beginning of October. Presumably, by October 12th, they started to make vehicles with AP2 hardware. They built only vehicles for overseas deliveries for the month of October. That means every vehicle delivered in the U.S. in October was out of the 5,500 overhang from Q3. It is usually not that extreme. Furthermore, U.S. vehicles weren't made until early November, and combined with delivery times using rail, there was really only about 1.5 weeks of deliveries in the U.S. in November. There were also some reports of running out of AP2 parts in mid November, but unclear if DS's were just coming up with reasons why orders were delayed. But in any case, it is clear that in the way the batching worked for Q4, the first two months of deliveries in the U.S. was going to be low, with a higher degree of variance than normal. So it isn't an issue that we don't believe the InsideEV's estimates. Instead, it is about the ramp speed for the AP2 hardware versions and the ability for Tesla to manage such extremes, as obviously they had extreme boom and bust along the delivery logistics.