Subaru Forester: Instruments and controls / Horn

To sound the horn, push the horn pad.
Other information:
Operating range
The system notifies the driver of another
vehicle approaching from either side when
driving in reverse. This feature helps the
driver check the rear and side areas of the
vehicle when moving backward.
If the system detects a vehicle approaching
from either side while moving backward,
it warns the driver of dangers in the
following way...
The performance and long life of your
vehicle are dependent on how you handle
and care for your vehicle while it is new.
Follow these instructions during the first
1,000 miles (1,600 km):
Do not race the engine. And do not
allow engine speed to exceed 4,000 rpm
except in an emergency...