[alffie]

In the NT whatever ADR is applicible to your car you MUST comply. Thats how LABOR brought in emissions in the NT. Before there was no emission requirements. Now all modified cars must go through the TAC ( including 9 inch conversions which causes some headaches if you had a 9inch conversion for years before they changed the rules) which will state the ADR you have to comply with. So if you can prove a 502 ram jet complies with the ADR and an engineer will sign off on it you can put it in any car you like.
They basicly have put the responsibilty on the engineer, If he says it comply with the INTENT of the ADRs MVR are happy.