here's the QLD brief, based on the ADR's regarding light vehicle ride height. other states have similar restrictions, contact your local road transport authority for more info http://www.transport.qld.gov.au/resources/...difications.pdf
pay attention to the bit that says:
Anyways, I live in melbourne, and I found this out when the police gave my mate a defect at a EPA/roadworthy blitz station... one of the items on the notice was "adjustable suspension", when we questioned it, we were informed that they were illegal as they allowed the user of the car to manually adjust the height of the car. They were only legal if either the adjustment nut was welded in place, or an approved tamper proof sticker was placed over it by a VASS engineer.