According to the State of Michigan, Act No.460 Public Acts of 2012,
" A person shall not transport or possess usable marihuana as defined in section 26423 of the public health code,
in or upon a motor vehicle or any self-propelled vehicle designed for land travel unless the usable marijuana is
1 or more of the following:"
(a) Enclosed in a case that is carried in the trunk of the vehicle.
(b) Enclosed in a case that is not readily accessible from the interior of the vehicle,
if the vehicle in which the person is traveling does not have a trunk.