1. A vehicular interior rearview mirror system, said vehicular interior rearview mirror system comprising: an attachment element adhesively attached at an interior surface of a windshield of a vehicle; an interior rearview mirror assembly comprising a mirror head, wherein said mirror head comprises a reflective mirror element; wherein said interior rearview mirror assembly comprises a mirror mount for attaching said interior rearview mirror assembly to said attachment element; wherein, when said mirror mount is attached to said attachment element, said reflective mirror element has a field of view rearward of the vehicle; wherein said interior rearview mirror assembly includes a pivot joint enabling a driver of the vehicle to pivotally adjust said mirror head to set the rearward field of view of said reflective mirror element to the driver's desired setting with said interior rearview mirror assembly attached to said attachment element; wherein said interior rearview mirror assembly includes circuitry disposed in said mirror head, and wherein at least two electrical accessories of said interior rearview mirror assembly share at least one component of said circuitry; wherein said interior rearview mirror assembly comprises a portion that does not adjust when the driver of the vehicle, with said interior rearview mirror assembly attached to said attachment element, pivotally adjusts said mirror head to set the rearward field of view of said reflective mirror element to the driver's desired setting; wherein said portion comprises a video camera, and wherein said video camera, when said interior rearview mirror assembly is normally mounted in the vehicle, has a field of view through the windshield of the vehicle; and wherein one of said at least two electrical accessories comprises said video camera.