An interior rearview mirror system for use in a vehicle includes a mirror support assembly for attachment to the interior of a vehicle. The mirror support assembly comprises a first electronic accessory such as an imaging sensor. A reflective mirror element is disposed in a housing, the housing being pivotally adjustable about the mirror support assembly via a pivot element. The housing includes second and third electronic accessories at least partially controlled by a microprocessor. The mirror support assembly preferably includes a wire passageway for wires passing into the housing for the reflective mirror element. The second and third electronic accessories may be a headlamp controller and automatic dimming circuitry, or may be selected from a variety of other devices such as a garage door opener, an INTERNET interface, a video device, a trip computer, a light, or other items. The mirror assembly may also be in wireless communication with an external device.