An accessory mounting system for a vehicle includes an attachment element attached at an in-cabin surface of a vehicle windshield of a vehicle. The attachment element has a mirror mounting button. At least one attachment member is attached at the in-cabin surface of the vehicle windshield local to the attachment element. An interior rearview mirror assembly has a mirror head and a mirror support. The mirror head includes a mirror reflective element and a mirror casing. The mirror support includes a mirror mount that is configured to mount the interior rearview mirror assembly to the mirror mounting button of the attachment element. A structure is configured for mounting to the attachment member and is configured to receive and be supported by the attachment member. The structure is configured to accommodate a forward facing camera having a field of view through the vehicle windshield.