Recommendation: Buy a Python. It's the same manufacturer as Viper and has the same set of options available. (In fact the window roll-up module, tilt sensor, glass break sensor, etc are identical regardless of which you buy!) The Python is lower in cost than the Viper and has none of the dealer-protection crap (a la no warranty unless you purchase a Viper from a Viper dealer) going on. This means with a Python you can spend far, far less on the equipment, put it in yourself, get the same capabilities, and still have a warranty. One heads-up -- be prepared to flash the unit you buy, which means make sure you get the kit that allows you to connect to your PC and flash it. You'll likely need to.