the license plate laser "foils" are meant to prevent photographs of your license plate. they do this by reflecting light at angles similar to what a photo-laser trap will use to snap your license plate. it does not scramble laser, nor is it of any use for other than photo-laser traps (unmanned traps).
there are scramblers out there that emit ir and are mounted at the obvious targets such as the headlights but i have yet to see any report that says that they work...
1993 300e-2.8 - gone now <sigh>
"Do not adjust your mind, it's reality that's malfunctioning"