The Rule that subclause 2.7(10 ) refers to is the "Land Transport Rule - Vehicle Equipment Amendment 2007 Rule 32017/2" not subclause 2.7(9 )
What subclause 2.7(10 ) is saying is that if Gazzeted an authority card can be issued to confirm that the exhause complies with MSNZ rules and is therefore excluded from compliance with this rule 32017/2.
“Motor sport vehicle means a Class MA or Class MC motor vehicle that is:
“(a) used in motor sport competition; and
“(b) operated in accordance with the conditions of a valid motor sport authority card issued to that vehicle by an organisation in 2.7(10).”
“Motorsport New Zealand means Motorsport New Zealand Incorporated.”
This is clearly in line with the "Objective of the Rule"....
...If a light motor vehicle covered by the Rule has been modified, so as to increase the noise output from its exhaust system, and the exhaust noise output exceeds that prescribed by the amendment Rule, the vehicle would have to be certified in the same manner as a low volume vehicle, under the Low Volume Vehicle Code....
http://www.landtransport.govt.nz/rules/ ... 07.html#21
An Authority card is LVV certification.
http://www.lvvta.org.nz/LVV%20Code.pdf
Annex 3 – Specific purposes covered by a LVV Authority Card [refer 2.12]
Compliance with the Appendix Two, Vehicle Safety Requirements for competitions under the National Sporting Code of MotorSport New Zealand Inc, covering only those components and systems that do not comply with applicable requirements for general use on the road and valid for a maximum period of 12 months only.
LVV Authority Card means a certification document, issued under the delegated authority of the Director, specifying alternative safety related equipment required by a vehicle for special purposes defined in Annex 3.
Also your questions are answered by the operation of subclause 2.7(10 ), if you have an authority card, you have a road legal car so thats what you use if you go to the dairy etc and 2.7(9 ) covers to and from the event.