My experience with the CHP has been what I consider "indirect". I have had fair-to-moderate success in getting Assignment Cards from Robert Read at the CHP. Not all of the cards are still around, and communication is sometimes extended, but we've gotten a few cards. Robert also sells some CHP-specific equipment.
We've also been able to confirm a car's CHP Unit Number by requesting a registration history from California DMV, as discussed here:
http://www.specialservicemustang.net...ead.php?t=2676
In this situation, the first owner has been listed on the report, and includes the first license plate number, which is the car's CHP Unit Number.
Some CHP owners are also members of the
CHP forum, where we've read in-service stories by the officers who drove these cars. Who knows what connections may be obtained through this kind of access.