the NSW "Light Vehicle Modification Guidelines" (VSI06) here:

http://www.rta.nsw.gov.au/registrati.../vsi/vsi06.pdf

and the similar Victorian "Guide to Modifications of Motor Vehicles" (VSI08) here:

http://www.vicroads.vic.gov.au/vrpdf/rdsafe/VSI%208.pdf

are both old State based rules that about to be (or have already been) supersceded by the National Code of Practice...

http://www.dotars.gov.au/transport/s.../vsb_ncop.aspx

The National Code of Practice for Light Vehicle Construction and Modification (NCOP) has been prepared by members of the Australian Motor Vehicle Certification Board Working Party in consultation with industry, user groups, government agencies and individuals with an interest in light vehicle construction and modification.

It is important to note that the NCOP is a "live" document and will be updated by the Working Party as required.

Please be aware that the NCOP only represents the technical requirements that must be met - administrative requirements are dealt with separately by each state and territory's administrative guidelines or business rules.
but still EVERYTHING must comply with the ADR's:

http://www.dotars.gov.au/roads/motor/design/index.aspx

summarised nicely here:

http://www.vicroads.vic.gov.au/vrpdf...e/VSI%2022.pdf


now this REALLY might be one for the stickies...

useful only if they bother to search before posting