You rely on your car to get you where you're going, so why not make sure that you car is as secure as possible? A cheap car alarm system will be sure to keep thieves far away. The best car alarm systems have adjustable sensor sensitivities and are loud enough to be heard from a distance. Some will even allow you to unlock your car door, a big benefit when you're carrying a lot of bags from the store. Thieves usually take the easiest pickings, so make sure that your car is hard to steal with a good car alarm system.