I respectfully disagree Sandman.
Once (just once) I got an early alert. V1 goes nuts, I slow (from 10 over to the limit). Must have been careless use of the gun, because 10 seconds later he was in sight and clocking me. He was around a curve or over a hill or something. I forget the particulars (it was years ago) but he was definitely out of my line of sight (and I his) on the first alert.
I will agree that every single other time I got a real lidar alert (not a false) it was because my speed was being monitored. Once the MD Trooper decided I was a small fish in a big sea (10 over again). All the other times, I spotted the OH Highway Patrol in their predictable positions on the Turnpike well in advance of being hit by the gun.
Funny story: Two weeks ago I spotted the OH Patrol and slowed to the limit. He clocked me (twice actually) at 64/65. He knew I had been speeding because I quickly (but safely) moved to the center lane once I saw him and slowed. My wife says he pointed at my V1 on the windshield as I passed, then jumped out into the far left lane from his center position. He followed at a discrete distance (out of my sight because I was in front of a rig), surely to see if I would jump back into the left lane and get on it. I continued at 64/65 until we hit the next break in the median and he sped up just before it so I could see him, then turned around and (I suppose) went back to his old spot.