A mounting assembly for mounting a mirror assembly and an antenna assembly with a vehicle cab including a radio which includes grounding the antenna assembly with the vehicle cab. The mounting assembly includes a conductive metal support rod connected with a mounting bracket formed of molded polymeric resin including a conductive filler. The antenna assembly includes an antenna mounted to a support which is secured with the support rod. Also, an antenna cable extends from the antenna through the mounting rod and the cab assembly in usual manner. The arrangement provides a conductive path to the vehicle cab and radio.