If a registered motor vehicle or trailer has been modified, a person must not use it, or permit its use, on a public street unless (a) in any case (i) the vehicle, as modified, complies with the relevant vehicle standards; or(ii) the modification is otherwise acceptable to the Registrar; and(b) in the case of a heavy vehicle, the modification complies with the National Code of Practice for Heavy Vehicle Modifications published by the Department of Infrastructure, Transport, Regional Development and Local Government of the Commonwealth, as Vehicle Standards Bulletin No. 6, as amended or substituted from time to time.Penalty: Fine not exceeding 20 penalty units.