Cadillac 1967 VVI Data Book page 149

The three-way, inside rear view mirror used on the Fleetwood
Sixty Special Sedan and Brougham can be adjusted for three
different types of driving conditions. For daylight driving, the
lever at the bottom of the mirror should be in the left hand
position. For normal night driving the lever should be posi-
tioned at the center of the mirror. Move the lever to the right
to counteract intense glare.
Remote-control outside mirror
Your Cadillac is equipped with a remote-control outside rear-
view mirror on the driver's side of the car. Movement of the
handle inside the car allows you to adjust the mirror to suit
your requirements. Rotating the mirror head in its support
permits additional adjustment so that the view into the
mirror is not obstructed.