Iowa Code Title VIII. Transportation [Chs. 306-330B] § 321.437. Mirrors

1. Every motor vehicle shall be equipped with a mirror so located as to reflect to the driver a view of the highway for a distance of at least two hundred feet to the rear of such vehicle. Any motor vehicle so loaded, or towing another vehicle in such manner, as to obstruct the view in a rear view mirror located in the driver's compartment shall be equipped with a side mirror so located that the view to the rear will not be obstructed; however, when such vehicle is not loaded or towing another vehicle the side mirrors shall be retracted or removed. All van or van type motor vehicles shall be equipped with outside mirrors of unit magnification, each with not less than nineteen point five square inches of reflective surface, installed with stable supports on both sides of the vehicle, located so as to provide the driver a view to the rear along both sides of the vehicle, and adjustable in both the horizontal and vertical directions to view the rearward scene.

2. Notwithstanding this chapter or chapter 321E, a combination of vehicles coupled together which is used exclusively for the transportation of passenger vehicles, light delivery trucks, panel delivery trucks, pickups, boats, and recreational chassis, may permanently attach a convex-type mirror on either or both of the vertical supports, forward of the steering axle of the power unit, provided that the mirror shall not extend beyond the limit of any other rearview mirror on the vehicle.