I can’t speak to the specifics of why it might sit for months in a parking lot before being moved. Maybe that’s due to shipping schedules. It’s probably economically related, because it would be cheaper to ship them on a cargo ship at once by the tens of thousands than by shipping them by a few dozen at a time.
However, I can say that if it’s sitting in a parking lot for months on end, the car company has no interest in selling them domestically.
Sitting in those lots because they don’t have the electronic modules to complete the build to make them legal to sell.
GM has the same problem with Chevy pickups from Ft. Wayne, storing them in Kokomo.