I might be wrong, but I'm quite sure you need to be invited to be a wild card at the World Superbike championship. Though you could possibly enter the support superbike races they run on the same Weekend. (part of the Aussie superbike champs me thinks)
My understanding about the Australian series is there are a lot more riders that run at the front of mid pack pace. So there is a high chance that you would be behind that mob having to learn a new track etc.
Sure, the experience would be very valuable, but I'm picking your 8k would be pretty much blown on that one meeting. Would you get more experience out of one Australian round than 5 NZ ones? I think not.
Three top running Aussies came over for this years NZ nats, and three went back home with out winning a championship, though admittedly 4 time Aussie champ Shaun Giles did go close. But that shows just how competitive the NZ series is.
Look at mylaps.com, even 12th place were doing 1.9's at the Manfield round.
As someone already mentioned in this thread, the South Island tracks are riders tracks, you go very, very well at Taupo and more recently you went well at the Manfield long track. I reckon you would surprise many down south with your pace.
My personal feelings are if it's experience you want, you will get more bang for buck contesting the 5 NZ rounds for your 8K, not to mention it is a shit load of fun.
Your still young, there is plenty of time to go overseas eh, and wouldn't it be much more worthwhile to go overseas a much faster and competitive rider than you are now?

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