Abstract: A pair of parallel support members extend behind and perpendicularly to the dashboard of an automotive vehicle at the sides of the opening of the dashboard. Guide devices are provided on the sides of the unit housing of audio equipment and on the support members in cooperative engagement for slidably mounting the unit housing behind the dashboard. The dashboard has a hole formed therethrough in close proximity with the opening therethrough. A slot is formed through the top or bottom of the unit housing equidistant from the sides thereof intermediate the front and back of the unit housing. A pin is secured in the unit housing in operative proximity with the slot and is accessible via the slot. The pin and the slot are mutually perpendicular. A key-operated lock is mounted in the hole through the dashboard.