I have collector registrations on some of my vehicles that come with use restrictions in exchange for a single "forever fee" that does not have to be renewed. Choosing this registration prevents me from using them as a daily use vehicles. Abusing this classification results in large fines. There are no exception passes offered for sale. I suspect this is the same with the registration in CA if you don't use your truck as an RV. Since you have a clause about getting service completed, perhaps you can schedule an appointment close to your destination and get your truck serviced before returning home? You would be following the letter of the law even if it was not the spirit of the law. If you were pulled over for improper registration, you would be able to show your appointment and they could even verify it was legitimate calling the shop or you would have the service receipt on the return home.
