If you are going up to Northland towards Kauri trees you need to bear in mind the following. The local natives and low life raping scumbags monitor any carpark that is a tourist hangout and when said tourists set out on foot for the twenty minute walk to see the giant of the forest/waterfall/kiwi nest or whatever the hell, their campervans or cars get done over.
If you are leaving your vehicle take your passport, camera, wallet etc etc and anything of value and preferably lock anything of value back in the safe at your motel.
This country has been hyped to the max as a "Clean, Green Destination" Don't believe the bull#$%*. It's safe enough if you use your head and think ahead but man, we have had many, many visitors to this country either killed, raped, robbed and generally f*cked over for me to give you this unfortunate warning.
Good luck. You would be better off touring the south of the country. The further south you go, the fewer the problems. Although that is all changing now. A Korean tourist was murdered recently by three white power skinhead lowlife scumbag idiots. And that was on the west coast of the south island. I could go on and on but it's too depressing. Also, don't try and sample the night life after dark because there are thousands of drunken idiots everywhere, in the city, in the suburbs. These idiots have NO IMPULSE CONTROL and when they are drunk it's even worse. PM me if you want specifics, it's pretty much race based I'm afraid. But it's not racist if the prison statistics and overall crime statistics point to a particular race. That is, 14 percent of the population but 40 percent of the prison population.
Go on, flame me out. But it's all true.