Horn
Pressaon 
the steering wheel pad
to sound the horn.
See also:
Inside the LFX
The Cadillac SRX's new LFX 3.6L direct-injected V-6 delivers an SAE-certified
308 horsepower (230 kW) and 265 lb.-ft. of torque (359 Nm), with
efficiency-enhancing features including direct inject ...
Dome Lamps
The dome lamps are located in the overhead console.
They come on when any door is opened and turn off after all the doors are closed.
Turn the instrument panel brightness knob located below the dome ...