Statistics have it that car thieves break into cars at a rate of one per 20 seconds in the U.S. alone. Thus, having an alarm system in your garage or driveway is a must and investing in sophisticated high-end systems - ear-splitting sirens, remote-activated systems, and automated sensors - is something that car owners are all saving up for and raring to have installed.

Car thieves are as sophisticated, mind you. While car alarm innovators are busy advancing their technologies, they are just as busy deciphering them. In a way, you are just a few months ahead of them if you regularly update your car alarm systems. Otherwise, you just have to pray harder that the car thief who'll get to break into your car is a novice or at least have not mastered your type of alarm system yet.

For people who want to buy the best driveway alarm system, what should you consider?

Know about the basics of an alarm system. In its simplest assembly, it is nothing but sensors connected to some sound-producing structure called siren. There is a switch to activate it when you leave the car and there are wires that conduct the "stimulus" to the siren that starts blaring when there is an attempt to break in.

Modern cars have more elaborate systems that typically consist of:

1. A range of sensors along with switches, pressure sensors and motion detectors

2. A siren that can wail to catch attention and make a distinct alert sound so that you know it is your car

3. A radio receiver for a wireless control from a key fob

4. An auxiliary battery so that the alarm continues even after it gets disconnected from the main battery

5. A computer control unit that monitors and controls everything; also called the "brain."

The sophistication of a driveway alarm depends on this brain which is actually a small computer. Quite typically, the smart system gets alerted when somebody cuts off the connection with the battery which is the main source of power. Since intruders will most certainly do this without switching off the alarm first, cutting off power triggers the blaring of the siren.

Know the two types of a car alarm security systems: the active and passive systems. The former needs to be activated and deactivated each time while the passive automatically activates when the motor is not running and the door closes. There is a wide array of hybrids and modifications that exist in the market.

You may want to add gadgets and systems that can help you deter burglars such as remote car starters. Make sure that when you decide to buy that the type you are purchasing is compatible with your car.

Finally, when buying a car alarm, make sure to ask about the range of the sensors. It is always best to buy one with a wide range. This will give you peace of mind when parking in an open area, but still not too sensitive that easily sets off when parked in tight places.

Whether you like it or not, car theft happens all the time. Installing all these does not warrant being 100 percent fail-safe, but thieves will have to expend more time and brain cells working around stealing than make it too easy for them to get away with your car.