According to my analysis VINs are produced in sequence, but are not released into production in sequence due to the fact that European cars were assigned VINs in large blocks, but are released into production gradually, to blend in with the production of cars for NA deliveries. There is also a certain disturbance to the sequence of VINs that are coming through the production due to batching as I explained earlier (
2Q 2013 Model S Deliveries Potential Surprise - Page 7).
I used this explanation to correctly predict the cars delivered in Q2. My prediction was 5200 vs. 5150 delivered actually, so I am quite confident that this theory was validated. (
Short-Term TSLA Price Movements - Page 341)
Regarding the VIN 21,591 reported by CygnusX-1 that was scheduled for the 9/28 delivery, it indicates that deliveries for Q3 will be approximately in the 5,400 range. Bear with the explanation below to see how this prediction was made.
According to the interview Elon did in Europe before the Geneva Auto Show this year Tesla planned to deliver about 5,000, "may be" 7,000 cars. Just recently there were reports on this Forum that European deliveries for this year are already booked. Assuming that Tesla allocated 5,000 spots for this year's delivery to Europe, there were 5,000 VINs assigned to cars for European Delivery. I have used lower 5,000 number because I think that while according the Elon NA orders are higher than expected, the pace of European orders did not pick up yet, so it is logical to assume that greater proportion of cars would be allocated for NA deliveries.
Assume that 5,000 European delivery cars will be allocated evenly: 2,500 for Q3 and 2,500 for Q4. Out of the 2,500 cars produced for European Delivery in Q3 about 1,500 would be delivered in Q3, while remaining 1,000 will be delivered in Q4 due to shipping/assembly delay (assumed about 5 weeks). Based on the above out of 5,000 VINS that were assigned to the European delivery cars only 1500 cars will be delivered in Q3. So the total quantity of VINs that are already assigned but are not going to be delivered in Q3 is 5,000-1,500=3,500.
The total quantity of cars delivered in Q4 2012 and Q1, Q2 2013 was 12,700. Calculating approximate number of predicted deliveries in Q3: 21,591-12,700-3,500=5,391.
Regarding the accuracy of the above prediction, the number could be different due to the following factors:
1. Tesla could have arranged production in such a way that the majority of European Delivery cars were produced in the first half of the Q3, so more than 1,500 of them are delivered in Q3
2. The production is about 600 cars weekly, so about 120 cars are produced daily. Therefore about 85 VINs would be delivered on a given day (600/7). So cars scheduled for delivery on 9/28 could have VINs 21,591+/-85.
3. According to my original theory linked below the most common configuration is S85 with air suspension, and VINs for these cars represent projected deliveries with the best accuracy. The post by CygnusX-1, however, does not mention the air suspension, so VIN 21,591 was assigned to S85 with coil suspension.
All in all I feel that 5,400 number arrived at above has a good chance to be higher by one to several hundreds.