Cars that show mpg on dash?
 

So I bought several gauges but found out that jap import cars don't use the OBD2 system.
But some jap import cars show km/l on the dash, such as the Honda Fit.
Do you know of other makes/models that do the same?

Nearly Honda models started showing this mid-2000's. I believe the Fit gained this in 2009, the Civic a bit earlier. Can't speak for other brands.

Most are configurable in settings.

l/100km is standard.

On all of my cars after 2000, it was configurable in the menus. (Toyota, MB, VW and Honda).

Chevy Astro (and GMC safari) vans that had the optional FCD could put it in l/100 km. I don't have the FCD, but I do have digital gauges and a button that switches between metric and standard (all stock setup). Oil pressure, temp, odometer, and speed all change to their counter part. I doubt you are looking for a van, but just saying that the option might be more common than you think.

Are you sure? All the Japanese imports to the US have used it since before 2000. New Zealand seems like too small a market to justify building a special non-OBDII version.

Anything post 2005ish should have it. 99% of Euros sold today will (I don't think Lotus does for example). But pretty much any 'normal' car sold within the decade should have a consumption read out.

Try Japan... in dozens of countries cars are sold with the JIS protocol.

I've got a 2008 G35x that displays MPG on the dash, it's a little generous on the mileage (about 5% high), but overall gives a decent representation of how well I'm doing. I have an OBD II splitter plugged in under the dash with a Scangauge II and Ultragauge plugged into it. Scangauge gives me temps, throttle position, etc. (stuff that doesn't get calibrated) and the Ultragauge gives me all the calibrated stuff (MPG, instant MPG, GPH, etc.).

Later Nissans/Infinities have it still. Average and instantaneous.

OBD2 is not mandatory in Japan
So if they are exporting Japanese market cars to NZ, they may not have OBD2 as they don't need them in Japan

https://www.carscanner.info/compatibility/