From the Mississippi State Highway Patrol web site on carrying concealed weapons:
§ 97-37-1. Deadly weapons; carrying while concealed; use or attempt to use; penalties.
It shall not be a violation of this section for any person over the age of eighteen(18) years to carry a firearm or deadly weapon concealed in whole or in part within the confines of his own home or his place of business, or any real property associated with his home or business or within any motor vehicle.
Note the "concealed in whole or in part . . . in any motor vehicle."