A module assembly suitable for attachment to an inner surface of a vehicle windshield includes a housing and a rain sensor. The housing comprises a first side, which is configured to be generally adjacent the inner surface of the vehicle windshield when the module assembly is attached to the inner surface of the windshield. The housing further comprises a second side, which is generally opposing the first side. The module assembly further includes a rearview mirror assembly mounting member provided at the second side of the housing for releasably mounting a rearview mirror assembly to the module assembly. The rain sensor and at least one other vehicular accessory are accommodated in the housing, which is adapted at its first side for attachment to the inner surface of the vehicle windshield by at least one of a mechanical attachment and an adhesive attachment.