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In some cases, I regret to have to report, a car stereo or similar audio device, whose controls and display are in Japanese language and/or Japanese kanji script, are (when intended for the Japanese market specifically and solely) utterly incapable of being changed to English language.
The ones that can be changed are generally the ones intended to be sold in a non-Asian or non-Japanese market.
The question in this case is, what is the maker and model # ***** your car radio? with that information, something about it could be determined, as to whether its language can be changed.
Generally the language is changed by going into the Setup, locating the list of languages, which might possibly be scripted in the appropriate script (i.e. Roman letters for English rather than 'English' spelled out in kanji.) Select the 'English' option, and approve the choice. It is remotely possible, that *if* the radio has the option of changing its language, you might be ale to find the
Setup - Language
option by somewhat random, or exploratory, button-pressing.
(Is the radio in Japanese kanji script, or is it in 'Roman' or Western-style lettering even if in the Japanese lanuage? if not in kanji, that is more hopeful, since kanji script implies a Japan-only marketing for the device.)