I'd say go for the not-so-expensive one, and the not-so cheap one...one that'll do just fine. I like the Black Widow alarm. It's not state-of-the-art, but if you're worried about your car being stolen or broken into in your driveway, or while your at the mall or something (hey, my brother-in-law's BMW got broken into at the mall), then get the Black Widow car alarm. It's like $400 for it. I'm goin to get it on mine...but i'm doing that halfly because i get a discount...