Hawaii Revised Statutes Division 1. Government § 291-54

The placard or disabled paid parking exemption permit shall be displayed in such a manner that it may be viewed from the front and rear of the vehicle by hanging it from the front windshield rearview mirror of a vehicle when the placard or disabled paid parking exemption permit is in use. If the design or condition of the rearview mirror, or the design or condition of the placard or disabled paid parking exemption permit precludes hanging the placard or disabled paid parking exemption permit in a secure manner, the placard or disabled paid parking exemption permit shall be displayed on the dashboard.