It involves a little work and three cars. But it works and gives you plausible deniability and you know when you need to ditch them. You take the plates from car #1 and put them on car #2 while taking car 2's plates and putting them on car #3. Make sure you know where car #3 is always parked. Take a picture of plates from car 2 that you put on car 3. Take car #3's plates and put them on your car. Then go by car #3 every day and if the plate you put on there is gone or changed you know it's time for a change. And if for some reason you get LE contact you play dumb and are the victim. There's two others saying the same thing happened to them. I've done this for years. Never had an issue.