Wrong actaully. The police are always one step ahead. The stealth detectors work by having a differnet IF frequency in them to the older ones, which the police detector detectors picked up. They also have better shielding to help reduce RF inside them which leaks out through the receive antenna ( so effectivly it transmits a weak frequency that the detctor detectors pick up ).
I can't say for QLD, but the NSW police can pick up the newer stealth radar detectors. I also believe they have a device now that can detect the laser detectors as well.
As Richad has stated, they are illegal in all states but WA. Not sure what the fine is in QLD, but in NSW if they detect one in your car your car can be pulled over, and you be asked to hand it over, in which you receive a $750 fine. If you refuse they can then search your car on the grounds that you are hiding one, and you then get issued with another $750 for failing to admit and hand over the illegal detector.
I would guess QLD would be similar, and its probably not worth even having it in your car.