Abstract: Vehicle window security shield assemblies and related methods of use and/or installation. In some embodiments, an insert-shield assembly may comprise an insert-shield with or without a separate inner shield, one or both of which may comprise a ballistic-rated, transparent material. The assembly may be mounted in and/or to one or more existing windows or other openings of a vehicle. In some embodiments, an inner shield of the shield assembly may be removeable from the assembly. In some embodiments, the entire assembly or a portion thereof may be removed to allow an officer or other user to use the removed portion as a portable shield. The removed portion may be returned to the vehicle following use to enhance the protection of the vehicle.