A mounting adaptor is disclosed for removably securing an interior rearview mirror assembly to a mounting support on the inner surface of a vehicle window such as a windshield. The adaptor preferably has a recessed channel on one side for receiving a window mounting button and a projection on the opposite surface simulating a window mounting button for removably mounting a rearview mirror assembly. The projection may be shaped to receive the same or a different mirror assembly channel mount as compared to the support on the window to allow conversion from one assembly to another without changing the window support. The adaptor may also include a support for a vehicular accessory such as a microphone, compass, headlight dimmer, light, moisture sensor, radar detector or the like. Such accessory is thus supported for convenient use by the driver or other vehicle occupant and in a highly advantageous operating position without interference with the rearview mirror, its replacement, interchangeability or adjustability. A wire cover may also be included on the adaptor.
An assembly combining a microphone and a support for mounting a rearview mirror adjacent a driver within a vehicle is also disclosed.