Thanks for asking your question. I’ve considered buying this unit for my husband. A friend of mine has it and highly recommends it. So do most reviews I’ve read.
Is the unit well forward on the dash? Or better than that is detector outside? Signal will not go through metal - roof of the car. My brother rented a car this week w/ one and the detector was mounted on the trunk. Detector was small - smaller than a box of matches. I have used a hand held unit on planes and it works well if you have a window seat. Won’t work if on an asile. To use my hand held in a car, have to put it against the windshield as far forward as possible.
Hope this helps.