Radar detector has certainly evolved since the '70 days of the fuzzbuster.
While radar detectors certainly work just not in all scenarios. With instant on radar, if they have not used it on the car in front of you then you will never hear that prealert and when he shoots you it will be too late.
Many law enforcement agencies have gone to laser (instant on also) those are very directional and they usually aim at at windshield or front lights and your car which may be a car or two behind will never pick it up.
I have used them in the past but not to purposely speed but to make me a more alert driver especially on long drives.
Be sure they are legal in your state but if you want to get one......a good one to look at but not cheap is the Valentine1 detector which does both laser/radar from front/back and sides.
Remember, never purposely speed and use cruise control as much as you can do you don't accidently speed.
Happy driving!
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For I know the plans I have for you," declares the LORD, "plans to prosper you and not to harm you, plans to give you hope and a future. Then you will call upon me and come and pray to me, and I will listen to you. You will seek me and find me when you seek me with all your heart.