From my post in the Ocean/Australia forum on airport transportation:

Also, here's contact info to hire a private car transport. It's 10k XPF for airport-to-airport in 4-seater SUV, vs about 3k XPF per person on the shuttle, vs. about 17-20k XPF for a taxi.

I asked the owner if it was ok to post & he advised me it was:

Harold Mary
email: [email protected] (not it's privat, not private)
Tel: (687) 96.16.95

Harold's a New Caledonia local - he asks that if anyone emails him for reservations to try to give him at least 24 hours in advance to book so he can ensure availability. Note - there is no Uber or anything like that & taxis, except at the airport, aren't just sitting around waiting for passengers.

One other factor of using a private car (it's about an hour drive) other than comfort, is that when the shuttles arrive, you have a lot of people getting their luggage and then standing in line. I got there about 5 minutes before 2 buses arrived and I was thankful I was able to get in line before the hoards (though I was flying QF and OW Emerald, I used the elite line)