Frequently Asked Questions on Police Lidar With the Lidar detectors on the market, you can detect lidar pointed at your car, but lidar measures your speed so fast you don't have time to react.
Details are in the FAQ, here's the summary.
If they target a car ahead of you, and you are ideally situated to detect the lidar, your detector might go off. Stealth in combination with a Lidar detector will save you at long range. If they are targeting cars at 1000 feet, and your car has reduced reflectivity, they don't get a speed reading until you come into range. Your detector goes off and you have time to slow down. At short range, if they point the gun at your license plate and you have a stealth plate cover, your detector goes off, and you have time to slow before they retarget another part of your car.