[Superfuelgero]

Probably due to the as-1 glazing. Most other windows are as-2 which is mainly just a light transmission issue. Since AZ allows full tint, there might be a loophole or no law on point. I'll pull it up in westlaw and take a look.

§ 28-957.01. Windshields required
A. The following vehicles shall be equipped with an adequate windshield:
1. A passenger vehicle, except a motorcycle, an all-terrain vehicle and a golf cart manufactured or modified before June 17, 1998.
2. A motor truck or truck tractor, except fire trucks, fire engines or other fire apparatus, whether publicly or privately owned.
B. This section does not apply to an implement of husbandry or to an antique, classic or horseless carriage automobile if it was not originally equipped with a windshield.

Note: Law has been challenged for vagueness, but the appellate court decided on the other claims without answering.

yadda yadda on tint

§ 28-959. Safety glass required; applicability; denial or suspension of registration; definition
Currentness
A. A person shall not sell and the department shall not register a new motor vehicle as specified in this section unless the vehicle is equipped with safety glass wherever glass is used in doors, windows and windshields.
B. This section applies to passenger motor vehicles, other than golf carts, including passenger buses and school buses. For trucks, including truck tractors, the requirements of this section for safety glass apply to all glass used in doors, windows and windshields in the drivers' compartments of the vehicles.
C. The director shall not register a new motor vehicle unless it is equipped with an approved type of safety glass. The director shall suspend the registration of any motor vehicle that is subject to this section and that the director finds is not equipped with an approved type of safety glass. The suspension shall continue until the motor vehicle is made to conform to the requirements of this section.
D. A person shall not replace glass or glazing materials used in partitions, doors, windows, windshields or wind deflectors in a motor vehicle with a material other than safety glass.
E. For the purposes of this section, “safety glass” means a product composed of glass that is manufactured, fabricated or treated in a manner that substantially prevents shattering and flying of the glass when struck or broken and that meets applicable federal safety standards.

/\ D says yes, E leaves the door open to them denying it (not as-1).

Potential work around
§ 28-2484. License plates for historic vehicles; definition
Currentness
A. The department shall issue special license plates for a historic vehicle on application and in the manner and at the time prescribed by the department. The license plates are in lieu of the regular license plates issued by the department.
B. The registration numbers and special license plates assigned to the historic vehicles shall be manufactured from Arizona copper and shall run in separate unique numerical series. The license plates shall be of a distinguishing color but different from the color selected for license plates issued under § 28-2482 or 28-2483.
C. On renewal of registration of a historic vehicle, the department shall annually issue symbols or devices as provided in § 28-2355.
D. The director shall grant the final approval of a vehicle to be licensed under this section.
E. For the purposes of this section, “historic vehicle” means any of the following:
1. A vehicle bearing a model year date of original manufacture that is twenty-five years old or older.
2. A vehicle included in a list of historic vehicles filed with the director by a recognized historic or classic vehicle organization during the month of December of each year.
3. A reconstructed vehicle that the director determines, on application by the owner, retains at least the basic original body style as manufactured twenty-five years or more before the date of the application.

Why?
§ 28-2485. Safety requirements; compliance
Currentness
Notwithstanding any other law, a motor vehicle that is eligible to be licensed under this article is in compliance with the safety requirements of the laws of this state relating to motor vehicles if the original safety equipment placed on the motor vehicle by the manufacturer of the motor vehicle is in good operating condition or if the original equipment has been replaced by equipment equal to or more efficient than the original equipment.

Since its, all safety glass its equal. Gets around Ariz. Rev. Stat. Ann. § 28-959(E) language of "applicable federal safety standards" (see id.).

The easiest way, whatever you want over a as-1 windshield. The laws only cover replacing, not doubling up. And tint type viability rules only cover "object or material placed, displayed, installed, affixed or applied on the windshield ". Ariz. Rev. Stat. Ann. § 28-959.01