Our production numbers are accurate, as are some of the other sources out there. They are basically measuring production at different times.
The other sources basically show the VIN range for the cars that went down the assembly line on a given day. This is a valid way to measure production, but
it can't account for cars that get held up in quality control. It's still great data to have available, so a big thank you to the people who provide it.
Since our data relies on window stickers, it won't show every car that went down the production line the day before because the window stickers for some cars
could get delayed. Our numbers are better described as showing how many cars have been built and are ready to get shipped to a dealer (as the cars have cleared quality control
and been invoiced to the dealer). However, the window stickers only include US and Canada bound cars, so the numbers will always be slightly less.
Which data is better? It doesn't really matter, take your pick. While the numbers vary slightly day to day, the weekly and monthly trends tell the same story.