One way is through the French lease system.
Thanks to the high taxes on new cars in France, all the major manufacturers - Peugeot, Renault and Citroen - run a so-called "temporary transit" scheme that is open to visitors from outside the European Community.
In theory, you buy a brand-new car for a minimum of 17 days and a maximum of six months and that car is bought back at the end of the trip. It is then sold second-hand as near-new, minus all the new-car taxes.
It can all be arranged through New Zealand agents (Australian also, for that matter) and the cars come with full insurance (no excess) and the promise of full-service back-up.
They can be picked up and dropped off at most major airports and major cities in France for free. They can be used in 40 countries, mostly European, and fees apply to permitted drop-offs in certain non-French cities.
My wife Shona and I booked a Citroen C3 diesel manual for $NZ1529 for 24 days (17 days plus an "early bird" special of seven days free). Extra days ordered in advance would have cost $33 a day.
We could have procured a petrol C3 for $1349, but because diesel is a little cheaper than petrol in France and a tank takes you considerably further, I decided on the convenience of paying more up front before leaving New Zealand. In the event, we were "upgraded" to a C4 because C3s were in short supply.
One of my brothers has used the scheme twice (with Renault), some New Zealanders have done so five or more times and there are loyalty bonuses for repeat customers.
While it might just about be possible to find some cheaper rental deals, particularly on shorter rentals, the scheme's popularity is borne out by the 2000 or so New Zealanders who use it each year.