Question? Why do you need to drive around with a shotgun in your car, and also if you need to ask these questions, that should be the first indaction that you probably should re think your plan.
I'm not sure how to respond to this... Do u have a CCW? I think perhaps you are in the wrong place.
NRA Certified Pistol Instructor & RSO, IDPA Sharpshooter, Project Appleseed Rifleman
Member NRA, GOA, SAF, VCDL