Abstract: An assembly is provided which is particularly suited for use as a mounting means for supporting a garage door radio control transmitter within a motor vehicle. The assembly consists of the garage door radio control transmitter and a housing therefor provided in the dashboard of the vehicle. The assembly is designed to be operable to permit the transmitter to be used either when supported in the aforesaid housing or when removed therefrom. The transmitter comprises an enclosure within which suitable electrical circuitry embodying conventional construction is housed operable to produce a signal which in turn is effective to actuate control mechanism for causing a garage door to open and close. The enclosure which is substantially rectangular in configuration is provided with a pair of end walls, one of which has mounted thereon terminal means operable for connecting the transmitter in electrical circuit relation with a suitable externally located electrical power supply.