What is the parking lot exemption for CCL holders in prohibited places?

Any licensee prohibited from carrying a concealed firearm into the parking area of a prohibited location shall be permitted to carry a concealed firearm on or about his or her person within a vehicle into the parking area and may store a firearm or ammunition concealed in a case within a locked vehicle or locked container out of plain view within the vehicle in the parking area. A licensee may carry a concealed firearm in the immediate area surrounding his or her vehicle within a prohibited parking lot area only for the limited purpose of storing or retrieving a firearm within the vehicles trunk , provided the licensee ensures the concealed firearm is unloaded prior to exiting the vehicle. This exception does not apply to any area where firearms are prohibited under federal law or to property regulated by the federal Nuclear Regulatory Commission.