An exterior rear view mirror assembly is disclosed which incorporates a warning light actuatable in conjunction with the vehicle turn signals to alert adjacent motor vehicles of an anticipated turn. The warning light is integrated into a first decorative cover member and may be connected to the vehicle turn signal circuit by way of connectable electrical leads or by an integrally formed plug and outlet arrangement. A second decorative cover member may be substituted for the first decorative cover member when it is not desired to incorporate the warning light.