321.404A  Light-restricting devices prohibited.
  1.  A person shall not operate a motor vehicle, motorcycle, or motorized bicycle on the highways of this state if it is equipped with a device that restricts the light output of a headlamp required under section 321.385 or 321.386, a rear lamp required under section 321.387, a signal lamp or signal device required under section 321.404, or a directional signal device as described in section 321.317.
  2.  A person who violates this section shall be subject to a scheduled fine under section 805.8A, subsection 3.
99 Acts, ch 13, §16; 2001 Acts, ch 137, §5; 2010 Acts, ch 1190, §52