I'm not aware of any ferry services but there are quite a few ro/ro ships that operate between NZ and OZ. Weblookup - Australia New Zealand shipping.
You'll need to do a bit of research about bringing a vehicle into OZ as its not as simple as ferry crossings in Europe.
Do a weblookup on DOTARS which has details on how to bring a vehicle into the country on a temporary basis.
Then depending on which State you arrive in will depend on the next steps - weblookup NSW RTA, QLD Transport or Vicroads all have details.