Just wondering what problems I'll face if I leave Australia 3 days after my WHV runs out? There's something I really really don't want to miss but it would mean staying here for 3 extra days. Also, I'm going to from here to New Zealand on a WH there, would it affect my entry into NZ?
Australian immigration won't take kindly to you overstaying your visa. You may get a hard time when leaving the country, but more importantly you could be banned from entering Australia for some time afterwards, possibly years. If I were you I would apply for a tourist visa to cover your extra days - it's a hassle but it's better than the alternative! It won't affect your entry into New Zealand though.
[ Edit: Edited on 05-Sep-2009, at 02:59 by bex76 ]
You will probably be banned for quite a few years from re entering. Apply for a tourist visa or go to New Zealand and then return on a tourist visa before you go back home and see the thing your really don't want to miss. It's better than the resulting ban and very likely problems in some other countries you may wish to visit which will receive information about you overstaying your welcome in Australia.
As far as I know, you'll be banned for 3 years. And since Australia and New Zealand are very close with boarder control, they might not let you in, thinking you'll do the same thing. Apply for a torist visa, don't leave it to chance.