(2) A person shall not drive a motor vehicle if driver visibility through the rear window is obstructed, unless the vehicle is equipped with 2 rearview mirrors, 1 on each side, adjusted so that the operator has a clear view of the highway behind the vehicle.


http://www.legislature.mi.gov/(S(v0gygab0ky0bwtf4lgkiud5i))/mileg.aspx?page=getObject&objectName=mcl-257-709#:~:text=(2)%20A%20person%20shall%20not,the%20highway%20behind%20the%20vehicle.