A windshield mounted, vehicular accessory mounting assembly is adapted to be small and compact and to reduce occupant injuries upon impact. The assembly includes a base and a coupling member releasably mounted on the base. The coupling member includes a support for mounting a vehicle accessory such as a rearview mirror. A breakaway fastening assembly extends through an aperture in the base to allow separation of the coupling member and vehicle accessory from the base should an impact occur. A series of projections extend between the periphery of the base aperture and the coupling member and are received in corresponding recesses to position the coupling member, provide a stable, three point connection, and prevent its rotation unless it separates from the base. The assembly may also include a swivel support arm to allow adjustment of the accessory position and to further reduce injuries.