1. An interior rearview mirror system for a vehicle, said interior rearview mirror system comprising: a mirror mounting button adhesively attached at an in-cabin surface of a vehicle windshield; an interior rearview mirror assembly comprising a mirror head and a mirror support; wherein said mirror head comprises a mirror reflective element and a mirror casing; wherein said mirror support comprises a mirror mount that is configured to mount said interior rearview mirror assembly to said mirror mounting button at the in-cabin surface of the vehicle windshield; wherein said mirror mount, when mounted to said mirror mounting button, provides a breakaway connection; wherein said mirror support comprises a first pivot element and wherein said mirror head comprises a second pivot element that pivotally attaches at said first pivot element to pivotally mount said mirror head at said mirror support via a single pivot joint; a forward facing camera disposed at said mirror support, wherein said forward facing camera has a field of view through the vehicle windshield when said interior rearview mirror assembly is normally mounted at said mirror mounting button at the in-cabin surface of the vehicle windshield; wherein said forward facing camera comprises a CMOS camera; and wherein said forward facing camera captures images for a collision avoidance system of the equipped vehicle.