OK, fun fact. As a word, prius wasn’t a wholly original coinage by the Toyota Motor Corporation. It’s a Latin word meaning “before” (adjective) or “previously” (adverb).
Related fun fact: in common law countries, it turns up in an old-fashioned bit of legal jargon — nisi prius (unless previously). Where a case was within the jurisdiction both of local courts and of the central courts in London, it might be listed for trial in London nisi prius meaning, it will be tried in London on a certain date unless the parties have previously had it tried in a local court. If a case was listed nisi prius, certain procedures would have to ensue — when it came on for hearing in London, th parties would have to aver that it hadn’t been dealt with in the local court and, when it was dealt with in London, a record had to be made to prevent it being re-litigated in the local court.
With reform of court organisation and procedures the term has had no contemporary relevance since, I think, about 1971, so it’s now obsolete. But older lawyers will still be vaguely aware of it, and it turns up in novels, plays, etc about, or situated in, the pre-1970s era, if they deal with legal topics. So there’s still some residual familarity with the phrase.
And, third fun fact: the pronunciation of Latin words in England has varied over time. In the nineteenth century it was common to apply English pronunciation conventions to Latin words. So, the title of Newton’s Principia Mathematica, for instance, would be pronounced “prin-sip-eye-ah math-eh-mat-ick-ah” (rather than “Prin-kip-ee-ah Math-eh-mat-ee-kah”, which is what a Latinist today would say).
Which means, of cousre, that nisi prius was routinely pronounced “nye-sye pry-us”. Lawyers, being a conservative bunch, retained the old-fashioned Latin pronunciation for legal jargon long after it has been dropped in other contexts. (They still say “prymah faysee” for prima facie, for example.) So anyone in England who is familiar with the phrase nisi prius is familiar with it as “nye-sye pry-us”.
And this may colour their pronunciation of the Toyota Prius.