True. But sorta Chicken s&*t.
It's in the all encompassing motor vehicle code which motorcycles are required to comply with.
Here's a link to click on:
http://www.legislature.mi.gov/(xxrfw...me=mcl-257-225
Here's the part they got you on:
(2) A registration plate shall at all times be securely fastened in a horizontal position to the vehicle for which the plate is issued so as to prevent the plate from swinging. The plate shall be attached at a height of not less than 12 inches from the ground, measured from the bottom of the plate, in a place and position which is clearly visible. The plate shall be maintained free from foreign materials that obscure or partially obscure the registration information, and in a clearly legible condition.
(6) A person who violates this section is responsible for a civil infraction.