Prior to AB whatever law enforcement could still issue a “non-correctable” ticket for loud exhausts. If you were a dick to the officer, they were a dick right back.
This new law just takes that out of the equation, probably thanks to those few assholes who just kept putting their car back to douche mode after getting a fix-it-ticket signed off.
And the same thing applies to things like window tint, tinting your headlights(?!?!?!?!?!?), or other dumb things that are very illegal.