The fees specified in this code, except fees for duplicate plates, certificates, or cards need not be paid for a vehicle of a type subject to registration under this code owned by a federally recognized Indian tribe that has entered into a mutual aid agreement with a state, county, city, or other governmental municipality for fire protection and emergency response, and the equipment is used exclusively for firefighting or rescue purposes or exclusively as an ambulance.
Source:
Section 9104.2, https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=VEH§ionNum=9104.2..