Drawing can provide hours of entertainment for the kids - get a CD case, some white paper, and a marker, and make a mini white board for continuous games and doodling fun. This one works great for long plane trips as well!
Have plenty of healthy snacks available for the drive - things that take longer to eat are the best, like raisins, nuts or carrots.
The old-school car game isn't quite out of style yet. There are plenty of different games to play that will keep the whole car amused, and may even provide a bit of a challenge! Hit up google for the rules to any of the following for some solid family fun:
Get the kids crafting with some car-safe sculpture aids. The options are endless with a roll of aluminium foil and a bunch of pipe cleaners. Set the kids a sculpture challenge, or let their imaginations run wild and see what they come up with!
Get the kids a disposable or instant camera and let them loose! If you go with an instant camera, bring along some empty scrapbooks and set them the task of documenting the holiday using photos, drawings and descriptions of what they see and do.
If you want to get creative, pre-make a scavenger hunt to be completed on the driving legs of your journey. Have a list of things the kids need to take photos of (the instant camera rears its head again) and things they need to collect along the way, like an ice cream stick from a dairy, a photo of them doing a handstand etc. (this plays in well with driving breaks and snacks).
Make frequent stops along the way, preferably at points that allow the kids to stretch their legs with a little run around. If you can stop where there are also toilet facilities, even better!
Get all your favourite family books on tape or download onto your iPod before the journey and enjoy listening to the stories all together. If you're kids are avid readers but struggle to read in the car, this is a great option to keep them happy.
There's nothing like a good old-fashioned sing along. Be sure to have the soundtracks to all your favourite family movies and get the whole car belting out the lyrics to Frozen for an hour or so.
Try to hold back the iPad or tablet as a last resort on your journey. If you go through all the non-tech games and activities first, being allowed to have an hour on the iPad towards the end of the driving leg will often get the kids excited again just before arrival. Using the iPad at the start of a long drive can often lead to complaining and arguments when it is taken away or the battery dies, so try to hold off on the tech toys for a while.
New Zealand is a stunning country and there is so much to see. Make sure you allow yourself plenty of time between destinations so you can get out and explore the beautiful places that you drive through. There are also plenty of walks along the main roads (well signposted by the Department of Conservation) that can provide great distractions and breaks from the long drives as well.