An exterior rear view mirror assembly incorporates a warning light (38) actuable 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 (36) and may be connected to the vehicle turn signal circuit by way of connectable electrical leads (54) or by an integrally formed plug and outlet arrangement. A second decorative cover member (72) may be substituted for the first decorative cover member (38) when it is not desired to incorporate the warning light.