Facts revealed - he was right , if 1 PU = $110 you could be hit with over 40k fine...but only 22k if you are an individual...
NSW Legislation
1) An owner of a motor vehicle is guilty of an offence if the vehicle emits excessive air impurities while being used.
Maximum penalty: 400 penalty units (in the case of a corporation) or 200 penalty units (in the case of an individual).
2) It is a defence to a prosecution for an offence under this clause if the owner proves that the motor vehicle was at the time of the commission of the offence a stolen motor vehicle or a motor vehicle illegally taken or used.
Therefore, always drive like you stole it 
NSW Legislation
21 Use of motor vehicle requires anti-pollution device
(1) An owner of a motor vehicle who uses the motor vehicle, or causes or allows it to be used, must ensure that each anti-pollution device that is required by this Regulation to be fitted to the motor vehicle is fitted to the motor vehicle in the required manner.
Maximum penalty: 400 penalty units (in the case of a corporation) or 200 penalty units (in the case of an individual).
23 Removal or adjustment of anti-pollution devices
(1) The owner of a motor vehicle who uses the motor vehicle, or causes or allows it to be used, must ensure that at the time of that use, any anti-pollution device that has been fitted to the motor vehicle has not been:
(a) removed, disconnected or impaired, or
(b) adjusted or modified and the adjustment or modification results in the emission of excessive air impurities by the motor vehicle.
Maximum penalty: 400 penalty units (in the case of a corporation) or 200 penalty units (in the case of an individual).
Don't let the cat out of the bag!