Here's an older article about these, and it does include the phantom plates. Cops around here will give you a ticket if they see something like this on the car. The plate can't be obstructed in anyway.
I would get it just incase I do it by accident one day. Not like imma be running redlights but some lights really are bullshit. I'll be at a redlight and out of nowhere see one flash on a car that had the right to go cause their light was green