An interior rearview mirror assembly for a vehicle includes a reflective element, a housing portion and a user input module. The housing portion is positioned at a perimeter of the reflective element and has an exterior surface that faces generally toward the driver of the vehicle when the interior rearview mirror assembly is normally mounted in the vehicle. The housing portion has a recess established at the exterior surface. The user input module includes at least one user input that is actuatable by a user and includes backlighting operable to backlight the at least one user input. The user input module is at least partially received in the recess at the housing portion and is configured to snap attach at the housing portion when at least partially received in the recess at the housing portion.