I took a look at 28-5432. it says it applies to:
http://www.azleg.state.az.us/ars/28/05432.htm
28-5432- This article applies to all of the following:
1. A trailer or semitrailer with a gross weight of ten thousand pounds or less and that is used in the furtherance of a commercial enterprise. (That's not me, I'm not a trailer)
2. A motor vehicle or vehicle combination if the motor vehicle or vehicle combination is designed, used or maintained primarily for the transportation of passengers for compensation or for the transportation of property. (That's not me)
3. A hearse, an ambulance or any other vehicle that is used by a mortician in the conduct of the mortician's business. (Definitely not me)
4. A commercial motor vehicle as defined in section 28-5201. (um, could be me, let's look that up)
http://www.azleg.state.az.us/ars/28/05201.htm
28-5201, says:
1. "Commercial motor vehicle" means a motor vehicle or combination of motor vehicles that is designed, used or maintained to transport passengers or property in the furtherance of a commercial enterprise on a highway in this state, that is not exempt from the gross weight fees as prescribed in section 28-5432, subsection B and that includes any of the following:
(a) A single vehicle or combination of vehicles that has a gross vehicle weight rating of eighteen thousand one or more pounds and that is used for the purposes of intrastate commerce. (Nope, no interstate commerce in my motorhome)
(b) A single vehicle or combination of vehicles that has a gross vehicle weight rating of ten thousand one or more pounds and that is used for the purposes of interstate commerce. (Nope, no interstate commerce in my motorhome)
(c) A school bus. (No school here)
(d) A bus. (Nope, I'm a private passenger vehicle, not a Greyhound)
(e) A vehicle that transports passengers for hire and that has a design capacity for eight or more persons. (No, private, not for hire)
(f) A vehicle that is used in the transportation of materials found to be hazardous for the purposes of the hazardous materials transportation authorization act of 1994 (49 United States Code sections 5101 through 5128) and that is required to be placarded under 49 Code of Federal Regulations section 172.504, as adopted by the department pursuant to this chapter. (No Hazardous stuff onboard here, well maybe if I have not dumped in a while)
I apologize in advance, I'm obviously missing something here.