Volvo Drivers, We are aware that late model Volvo Big Trucks have a problem with mounting an antenna in the factory location. The stud is weak, the factory coax is low grade. If you try to mount a bracket on the "mirror arm" you risk damaging the mirror arm and you will not get a satisfactory ground. We have a "Pin" (also known as a "Bird Perch") to replace the Torx bolt that mounts the mirror arm to the door frame. That bolt is grounded to the rest of the chassis to give your antenna system the ground it needs for best performance and SWR