Most remote car alarms are factory fitted by the maker or retailer of your car. Older cars may not have a remote control feature. If this is the case you can have a more modern car alarm fitted privately.

Average remote car alarms work from a distance of ten to twenty yards, but others will operate some of the car's functions from a quarter of a mile away. A basic remote car alarm will lock the doors and the boot, but more advanced models will also disable the engine.

Then there are other remote car alarms that will automatically close any open windows and the sunroof when the alarm is activated adding an extra layer of security to protect your vehicle. The most modern kinds of remote car alarms also have a function to start the engine from a distance or even regularly.

This comes in handy on a cold day. For example, you are approaching your car across the supermarket car park on a freezing cold day; click! You switch on the car's engine from several hundred yards, so that the heater has warmed the car before you get there.

Other remote car alarms will start the car on a regular basis for you, so that, if you go to work at eight o 'clock every morning, you could set the car to start at seven fifty so that the engine is warm by the time you are ready. This function can also start your car every day while you are on holidy so tht the battery does not run down.

Older remote car alarms work off small AAA penlight batteries, but the more modern ones run on even smaller lithium batteries the size of coins so that the remote control unit is not a big lump in your bag or pocket.

Furthermore, older remote car alarms operated the car's security devices by sending a beam of light or by issuing ultra-sound limiting their range quite considerably, but modern remote car alarms use radio waves which can be transmitted and received over far greater distances, typically well over a quarter of a mile.

It is fairly easy to fit a basic remote car alarm yourself or maybe with a little help, but the more complicated devices are probably best fitted by a specialist which will put the price up, of course. However, at the end of the day, it is cheaper to fit a good remote car alarms than to retrieve, replace or restore a stolen car, especially if it is vandalized as well.