A bill has been approved by the Michigan legislature to allow for the attachment of a tow ball, bicycle rack, removable hitch or any other device designed to carry an object on the rear of a vehicle even if it obstructs the rear license plate.
https://www.sema.org/sema-enews/2018/19/michigan-bill-to-ease-towing-restrictions-sent-to-governor
https://www.sema.org/sema-enews/2018/19/michigan-bill-to-ease-towing-restrictions-sent-to-governor