I have a Ford Security system. Didn't come stock but Ford threw it in as an incentive to buy. Funny thing is, it uses another blinky light which they mounted in the blank panel next to the rear defrost button. So now my car is like an airport blinking in there at night (the original LED still blinks as well).
[EDIT]My alarm chirps and uses a real alarm system, not just a horn (not that thieves really care either way).[/EDIT]
