The first 2 digits of the VON mean something. Sometimes
(like in the case of Superbirds or 440 Darts etc., it's the first 3 digits.
If the car was an internal-order or internal-handling, it usually got a "00" VON prefix. Keep in mind that could mean employee purchase. If it wasn't a show car but had someone's blessing inside Ann Arbor, its VON begins 00.
VON's also do not get doubled up, A sunroof car with ties to Corporate will have a 00 VON, not an M.
01-09 are the zone the car was destined for, either because the sales bank existed there or because that's where the allocation went, thus the common Y codes. 01 is Maine and 09 is Hawaii. Now you know where Mr. Norm was or did some horse trading when some of his T/A's were ordered.
Add to that the third digit, which breaks the zone location down further.
Everything else, from 1xxxxx to 5xxxxx began life on a dealership order blank. The order blanks are sequentially numbered, the pads were distributed broadly without care for zone or anything else. While you can trace say VON 172553 to Mr. Norm's, 171553 might have come from Hertz rent a car in Phoenix.
Then you have the letters and numbers, again meaning something, in fact they actually relate directly to Reynolds and Reynolds accounting codes that are still used today.
Here is a tag to add to your collection if you don't have it already.