How to Buy and Install a Car Radar Detector

Radar detectors can help you avoid getting a speeding ticket. Here's how to get a radar detector installed in your car.
Written by Elaine Sulpy
Reviewed by Carrie Adkins
One device that some people use to help avoid getting pulled over and given a speeding ticket is a radar detector.
Radar detectors
are small devices that can be installed in your car to help a driver "see" if there is an officer nearby. These devices sense doppler radar guns, which are frequently used by law enforcement to detect speeding vehicles.
According to the American Automobile Association (AAA), radar detectors are legal and permitted for passenger vehicles, but prohibited for use by commercial vehicles in all states except Virginia and the District of Columbia.
However, as with many driving laws, actual restrictions can vary by county or jurisdiction—so be sure to check with your local state law enforcement prior to purchasing and installing a radar detector system.
Of course, you can't always prevent yourself from getting pulled over. And when you do, you need to have
car insurance
If you’d rather leave the hard work of gathering quotes to someone else, use Jerry. The Jerry app can collect quotes from more than 50 top insurance companies, like Travelers, Nationwide, and Progressive, in seconds! They even help cancel your old policy once you’ve made your pick.
Let Jerry find your price in only 45 seconds
No spam · No long forms · No fees
Find insurance savings

What is a radar detector?

A radar detector is a device you can install in your car to alert you when a police officer is using radar nearby.
These devices pick up on the radar waves emitted by radar guns and tell you that there are radar waves nearby, allowing you to slow down in advance (though you shouldn't be speeding, anyway) before you get speeding ticket.
Safety Tip Remember to stay within the speed limit and practice safe driving.

Know the difference between radar and lidar

One key factor to keep in mind when selecting a radar detector is understanding the difference between radar and lidar. Radar is an acronym for "radio detection and ranging" while lidar is an acronym for "light (laser) imaging, detection, and ranging."
Not all law enforcement officers utilize radar, so if you purchase a radar detector that cannot also detect lidar, you will not be able to detect law enforcement that use lidar.

How to buy a radar detector

Devices range in price from about $100-$200 for a radar detector unit, with those that can also detect lidar ranging slightly higher.
Considerations to make when purchasing a radar detector include:
  • The ability to detect radar and lidar
  • Range of the device
  • Connectivity to your vehicle (remote, cordless, or wireless)
  • Additional features, such as voice alerts

How to install a radar detector

Not all radar detectors are installed the same and the following steps are a general approach to installing a radar detection system. Steps will change slightly depending on whether you have a corded, cordless, or remote system. Always follow the instructions that came with your product.
To install a radar detector in your car, follow these steps:
Step 1: Check the law. Check with any local or state laws regarding placement of the device. Some locales have laws that state a device must be placed in a specific place on your dash or windshield.
Step 2: Read the manual. Read through the entire instruction manual before you install your device. There may be steps or instructions specific to the device you purchased that may not be covered in this guide.
Step 3: Get the tools. Make sure you have all tools on hand. Tools to install your device may include window cleaner (to properly adhere a suction cup to the window) and batteries (for cordless systems).
Step 4: Install the system. Steps to install your system will depend on whether you purchased a corded, cordless, or remote system. The differences in installation steps follow:


A corded system gets it power from your vehicle. To install a corded system:
Step 1: Mount the device.
Step 2: Plug it in. Plug the device into your car’s cigarette lighter. Note, if the system recommends it is connected to the fuse box for power, it is recommended to seek professional assistance.
Step 3: Turn it on. Turn on your car to power up the system and turn the device on. You should be able to detect radar or laser, depending on the system you purchased.


A cordless system will typically receive its power from batteries. To install a cordless system:
Step 1: Install the batteries. Before mounting a cordless system, it is recommended to first install a fresh set of batteries.
Step 2: Mount the device.
Step 3: Turn it on. With a cordless system, you do not need power from your vehicle to run the device. Simply turn it on and you should be able to detect radar or laser, depending on the system you purchased.


A remote system must be installed by a professional and should not typically be installed by the end user. There is wiring that must be installed, and often the dashboard of your vehicle will need to be removed.
Using a radar detector can help alert you to nearby law enforcement, keeping you from getting a pricey speeding ticket and subsequent raise in your
insurance rates
Haven’t shopped for insurance in the last six months? There might be hundreds $$$ in savings waiting for you.
Judith switched to Progressive
icon savingsSaved $725 annually
Alexander switched to Travelers
icon savingsSaved $834 annually
Annie switched to Nationwide
icon savingsSaved $668 annually
Are you overpaying for car insurance?
Compare quotes and find out in 45 seconds.
Try Jerry

Easiest way to compare and buy car insurance

No long forms
No spam or unwanted phone calls
Quotes from top insurance companies
Find insurance savings