Fact #1 when people buy NZ new car and want extras, e.g. weather liners or leather seats, they have to pay extra.
Fact #2 when people buy Japanese mported cars, they mainly buy them because they are significantly cheaper than new. Nevertheless when it comes to extras, the expectations more often than not is for the dealer to throw them all for free.
I had that conversation with numerous dealers who know exactly how much extras cost, but would rather "pretend" they do not know about them, or would even say "not possible" because they know exactly that buyer will expect it to be done at no extra charge.
It is not mandatory to sell cars with interface of the stereo or modern instrument cluster (speedometer) being in English, it is not mandatory to provide owner's manual in English, hence expectation for that to be done by the dealer at their cost has no grounds, despite the fact manuals are available as well as conversions and stereos for many popular makes and models.

Those dealers who change stereo, or/and convert dash upfront do incorporate cost in the sales price and they only do that for cars in a certain price range... Others would never bothered adding any extras regardless of the sales price..

FYI: the list of 2014+ models where Instrument cluster (speedometer) conversion to English is possible:
Toyota: Axio, Fielder, Vitz, Auris Hybrid, Aqua (2012-2020), Crown Hybrid, Harrier, Sienta Hybrid, Prius(2010-2014), Prius PHEV (2012-2014)
Honda: Fit, Grace,Vezel
Suzuki: SWIFT
Mazda: 2012+ Atenza, CX-5, CX-8
Nissan: Leaf (2011-2020)