Tesla S Owner's Manual page 51

Mirrors
You can turn the auto-tilt feature on or off
using the touchscreen, Touch Controls >
Vehicle > Mirror Auto-Tilt.
Note: Depending on date of manufacture and
options selected at time of purchase, some
Model S vehicles are not equipped with Mirror
Auto-Tilt.
Rear View Mirror
The rear view mirror is adjusted manually.
Except when in Reverse, the rear view mirror
automatically dims in proportion to the level
of glare from the headlights of a vehicle
behind you.
50 Model S Owner's Manual