Yeah, but is a couple of infrared lights enough to be considered "police"? What if I yell "VWEEEWOOOWEEEOOO" and someone mistakes that for a legitimate police siren -- am I still impersonating police, or is that person incredibly stupid?
If you say "Here's some infra-red lights. They simulate enough of a police car for other cars to change their behaviours" you're not going to have a fun time in court.
Why does everyone think that the entire law system is like tax code and finance laws? You (usually) can't just break a law because you found a technical loophole.