Not cars, but would like your thoughts.

gammelvind, May 31, 9:21am
Was thinking about building one of the oil burners to heat the house, like the idea that it will burn any type of waste oil cleanly, plus the fuel is free. Plus most of the bits are available via dumpster diving. Anyways what do you guys think!

http://www.murphysmachines.com/waste_oil_heater.html

murph2068594, May 31, 10:15am
Looks like a good idea, yet i would be checking with your local council first.
The words "burner" and "boiler" will definitely get their attention, the last thing you want to do, is install it and they find out. No Permit. Disable or Remove etc, etc, this heater from your house.

On the same note, your council will also be able to tell you if these can be "Legally installed in New Zealand".