This is something that can vary. Each dealer is alloted a certain number of cars based on their sales history. Because of this, you can sometimes walk in the door to order a car and if the dealer already has a car heading for production based on their allotment, you can get a VIN pretty quickly as the car is really already slated for production. If the options you order are close to the base the dealer has ordered, this can be changed quickly and you get a VIN quickly. As an example of my experience back in late 2003, my dealer was being alloted 2 545's a month (early production and a small market dealer). Because of this, when I ordered, I literally had to wait until the next month to get a slot in production, hence the delay. It still happens that way sometimes, but other times a person walks in the door and orders a car and the only difference is the paint color and adding Sirius at the factory and the dealer can adjust a car already ordered...