First of all, you have to find out if radar detectors are legally permitted in your area. It is important to know all the laws and rules regarding detectors. If radar detectors are illegal in your state then you may have to face certain fines or punishments. Consider visiting the website of your country's department of motor vehicles, or any legal adviser, to familiarize yourself with all the applicable laws.

After that, you have to decide on your budget. There is a very big range of radar detectors available in the market. Prices start from around $60 and go up to approximately $500. Select the best one that you can afford.

Next, decide which type of radar detector you want to purchase. Radar detectors are available in three types: cordless detectors, corded detectors, and one which can be controlled by a remote. Corded radar detectors are fixed in your car's windshield; cordless radar detectors are completely movable from one place to another, and remote controlled radar detectors can only be operated by their remotes.

Before buying a radar detector, you should know each and every feature of it. Some of these features are things like range, audio-video alerts, and alarms etc. However, it is not necessary that every radar detector must have all these features. You should also be aware of the names of all big brands that are available in the market.

Some other points to keep in mind are:

• The sensitivity of the detector should be at least 110 dB.

• Look for one with a display that you are able to see clearly, both at night as well as in bright sunlight.

• Also, see whether it has a mute feature along with volume control.

• Finally, select the best one which suits you and your budget.

Now that you have decided on your budget, and come to know which particular brand you want and all the basic features of it, you can start researching your radar detector. There are many ways to search for radar detectors. You can search on the internet where you can not only get information, but you can do comparisons with different brands also.

Next, decide where you will buy your radar detector; from an online store or from your local electronics shop. If you know how to install a detector, you can do it yourself, otherwise get it installed by an expert. To get the best results, always install your radar detector facing towards the windshield of your car.

You should always have the full information about the dealer from which you are purchasing your radar detector. Always ask for a warranty. Always call the person and talk to him/her personally while shopping online.

So after reading this article, you will not be left with any doubts regarding what points you should keep in mind while purchasing a radar detector. Since radar detectors are not only made for security purposes, but to be used in personal vehicles also, always keep in mind that if you are purchasing one for commercial use then you should check the legal information first.