Laser shield license plate cover? Do they really work or is it a bunch of hype?
What about Laser and Radar jammers?
How do I check the validity of these products?

 

All the stuff I've seen on these usually ends up saying they're crap. Do jammers work? Yeah but not as far out as Police can use them (they can hit you from like 1/2 a mile away and the BEST will usually work within, say, 1/4 mile range).

As for the license plate stuff, that's usually just to shield your license plate from cameras. I'd say they're probably B.S. too. They supposedly work from "known camera angles" but no angle is known since all cars are different heights and the camera can be mounted on a stoplight or something lower like a street sign.

The only real thing that you can do to try to make your car more stealthy to radar & laser is to keep anything shiny off of it (chrome, polished metal, license plates, etc.) so basically, if you like a clean good looking car, you're screwed anyway!