Sorry no one posted before the end of the weekend to your question. If you DO NOT have a concealed carry permit from NC then your shotgun has to be UNLOADED and ammunition stored separately. Now if you DO have a permit, according the the dept. of safety website (www.tennessee.gov/safety),
Public Chapter 431 – Loaded Rifles and Shotguns in Vehicles – This act allows a person with a handgun carry permit to possess a loaded rifle or loaded shotgun in a privately owned vehicle. The act provides that the weapon cannot have ammunition in the chamber except in the case that an individual permit holder feels physically threatened.
Effective Date: June 12, 2009.
Not many police officers know this but I have found out that State Troopers generally have a better understanding of carry laws here in Tennessee. Hope this could have helped you out!