All parking on state capitol grounds excluding parking in metered areas shall be authorized through the issuance of valid parking permits. These permits shall be issued by the director to state officials, state employees, state agencies for official cars and to such other individuals as determined by the director to require parking to aid in carrying out state business. These permits shall not be transferred from one vehicle to another except as authorized by the director. All parking on state capitol grounds shall be for official purposes only. Parking spaces may not be used for other purposes such as the conduct of private business or the storage of personal property.