A day/night rearview mirror assembly for vehicles useful in varying climatic conditions provides improved control and shifting between day and night positions, reduced undesired movement between day and night positions during adjustment of the major mirror position, and improved impact and bending resistance. The assembly preferably includes a molded mirror case, a prismatic mirror element and a two piece actuator assembly which provides consistent day/night shifting pressure in all temperatures. At least one stop member on the case back is included to limit actuator movement and precisely control day/night shifting. Cam surfaces on the actuator and stop member aid assembly. Downwardly opening support members pivotally mount the actuator assembly and prevent actuator movement toward the mirror element even upon impact. Ramp shoulders adjacent the support members also restrict actuator withdrawal. An extending lip on the actuator toggle limits movement of the separate actuator pivot member toward the mirror element upon impact and aids actuator installation. An improved actuator toggle having an integral retainer for a ball joint clamping member is also disclosed.