321I.9  Exempt vehicles.
  Registration shall not be required for the following described all-terrain vehicles:
  1.  All-terrain vehicles owned by the United States, this state, or another state, or by a governmental subdivision thereof, and used for enforcement, search and rescue, or official research and studies, but not for recreational or commercial purposes.
  2.  All-terrain vehicles used in accordance with section 321.234A, subsection 1, paragraph “a”.
  3.  All-terrain vehicles used exclusively as farm implements.
2004 Acts, ch 1132, §52; 2007 Acts, ch 141, §34; 2012 Acts, ch 1100, §41