At one point, you could request registration history on a vehicle, as discussed here -
http://www.specialservicemustang.net...ead.php?t=2676
However, lately there have been members who were not able to get the paperwork from DMV. It may be related to privacy laws now in place which prevent this information from being given out.
The best way to determine where a car served is by obtaining (a copy of) the CHP Assignment Card. Many of the cards have been destroyed, but we have had some success previously in obtaining them. Lately, we have not been able to get them through our current source, but there are a couple of members who are working on other angles to gain access to the information.
Sometimes, CHP paperwork will turn up that will identify where cars served. Here is an example of how a CHP letter to Ford about warranty work allowed us to document a bunch of cars -
http://www.specialservicemustang.net...info170160.htm