Hmmm .. two key points:

"Noise control equipment can be considered defective where it ... has, in
the ***opinion*** of an authorised officer, been modified in any way that
makes it less effective than it would have been if not for the modification".

ie. some (OK, most) aftermarket cans are desired because they make more noise
therefore all aftermarket cans are automatically defective?

"Use of informed subjective assessment to decide a noise offence is central
to NSW noise legislation. <snip> Powers under the POEO Act and existing Noise
Control Regulation enable officers to exercise judgement in deciding whether
noise is an issue."

No problem with this if the assessment truely is informed, subjective,
reasonable
and impartial. The underlying arguement seems to be that this **testing**
is pretty expensive and time consuming so we'll settle for "if it's too noisy
for our officer then it's too noisy for the neighbourhood".

I thought our legal system had some fundamental requirement for substantive
evidence? Imagine "I think you were going too fast because most people who
drive WRXs drive fast so I'm issuing you with a speeding ticket"? :-)

Cheers,

Peter