Yes you can report it..
A friend of mine had a low r33.. he was going over few bumps, and bottom of his car scraped and few sparks came flyin out the bottom..
The car behind him thought he was throwing cig buts out..
Anyways so few weeks later he got a warning in the mail..
So yes you can report, but sorry not to sure to who..
maybe the police??
coz i know its like a 60 buck fine for literling