[Treeve]

In NSW if you being in an ICV from inter-state you will need a NSW engineers certificate relative to the vehicle as you have brought it in. Therefore you're up for re-inspection and recertification costs.

You will need to remain compliant with the emissions laws for your vehicle at the time, so expect an emissions and noise test.

Side pipes are legal in NSW, and have been since 2007.

Treeve (an ICV specialist engineer, coincidentally).