I would not count on option 1 existing for long. It’s a moving target.
option 2 is an option but it’s a bit of luck as to if it passes. I haven’t looked at in many years.
have you called NZTA as a start?
then Subaru nz for figures, they may have ones older than 10 years if you are lucky. They may even send you email to use as part of submission.
Burden of proof is on you so make sure you have it covered well.
do you have the Japanese paperwork for the car?
production numbers are worldwide not American ones which are online a lot.
you need to supply an article saying it a collectors item not just a review, though review will say it’s a performance model.
Depends on how the split the models as well WRX vs STI.
You also can’t sell the car for 4 years or use it for work.
https://vehicleinspection.nzta.govt.nz/__data/assets/pdf_file/0004/49738/Application-for-SIV-permit.pdf
option 3 put a cage in it and then frontal impact doesn’t apply as the airbags etc have to be removed