It is built right into the car, so I don't think you will find it like you would on an aftermarket installed alarm. It is wired right into the stock door switches, horn, computer, steering column, etc. etc.
You will know you have one by locking the doors with the windows rolled down. close the doors, give it a second or two. Now, reach in through the open window, manually unlock the door or manually strike the power door lock button to the "unlock" position (as if you have broken into the car), and open the door. The horn (if it works) should sound. Meanwhile it has shut down the ignition system until you insert the key in the door and unlock it using the key as normal.