you would probably have to refer to the relevant ADR
http://www.infrastructure.gov.au/roa...dr_online.aspx



AUSTRALIAN DESIGN RULES
Any modification to a vehicle (whether or not listed in the Order) has the potential to affect one or more ADRs. Unless exempted by RMS (or ADRs do not apply to that vehicle), any modification that affects an applicable ADR will require certification; for example, a pole-mounted information technology (IT) screen is likely to affect one or more ADRs, and if this is the case, a VSCCS certificate will be required for the modification.