Here in NC, with a concealed carry permit, yes, you can have the firearm loaded and within arm's reach in the vehicle. You can even have it holstered while you're driving if you so desire. You just have to inform an officer that you are a permit holder and have your gun with you if you are pulled over. I carry a Springfield subcompact 9mm every day. It fits perfectly in the door.
Without a concealed carry permit, the firearm is supposed to be unloaded and in plain sight.