I've seen that crap sold for years!
Laser and photo reflective spray replaces the "clear" license plate covers that many municipalities now ban. Here in NYC we have photo equipment at nearly every intersection in some areas. They automatically snap a pic of the vehicle as it passes a red light, or doesn't pay a toll, and mails a ticket to the registered owner.
Two thoughts:
1. You can accomplish the same result with any aerosol-based hairspray. Spray, and unless it gets wet, it will last about 2 days.
2. It's a crime to evade a toll in NYS. Not a vehicular violation - a penal law crime. IMO, not worth it.
PS - It aerosol sticks to the license plate, which has a glossy tone, and causes "bounce-back" of the light into the camera's lense - rendering the plate # illegible. The aerosolized film on the plate, when hit with the flash of ligh from the camera (at night), or simple daylight (the sun) does make it hard to read. It's also really easy to spot a car that's doing it if you're on the road as well. Here in NY you'd get pulled over in about 14 seconds if a cop saw your plate looked all shiny & ultra-reflective!