Mich. Comp. Laws § 750.227d: Transporting or possessing firearm in or upon motor vehicle or self-propelled vehicle designed for land travel; violation as misdemeanor; penalty.

Sec. 227d.

(1) Except as otherwise permitted by law, a person shall not transport or possess in or upon a motor vehicle or any self-propelled vehicle designed for land travel either of the following:

(a) A firearm, other than a pistol, unless the firearm is unloaded and is 1 or more of the following:

( i ) Taken down.

( ii ) Enclosed in a case.

( iii ) Carried in the trunk of the vehicle.

( iv ) Inaccessible from the interior of the vehicle.

(b) A pneumatic gun that expels a metallic BB or metallic pellet greater than .177 caliber unless the pneumatic gun is unloaded and is 1 or more of the following:

( i ) Taken down.

( ii ) Enclosed in a case.

( iii ) Carried in the trunk of the vehicle.

( iv ) Inaccessible from the interior of the vehicle.

(2) A person who violates this section is guilty of a misdemeanor punishable by imprisonment for not more than 90 days or a fine of not more than $100.00, or both.