The following is an extract from:
http://www.transport.qld.gov.au/qt/driver.nsf/files/images/$file/Vehicle-Modifications.pdf
which can be found here:
http://www.transport.qld.gov.au/qt/driver.nsf/index/vehiclemods
here is the extract:
Lowering or Raising of Vehicles
The road clearance of a motor car must not be less than 100mm
measured at any part of the vehicle other than the wheel rim
or brake backing plates. (This does not apply where a lesser
clearance has been specified by the manufacturer.)
When lowering or raising a vehicle body (front or rear):
• the suspension travel in the bump or rebound mode must
not be altered by more than one-third of that specified
by the manufacturer;
• coil springs are to remain in locating seats on full
suspension droop without forcibly being removed.
In addition, the normal relationship between the front
and rear suspension heights must not be unduly affected.
Suspension coil springs must not be shortened by cutting.
Leaf spring suspensions must not be raised by the use of
extended shackles or adjustable metal plates. If lowering
blocks are used, they must be either steel or aluminium.
[Edited on 9-7-2004 by MikeM]
