The used vehicle prices seem very high compared to past years,
but if the NOx pollution regulations are going to be tightened to such an extreme that gas/diesel engines will be BOTH expensive and get worse fuel economy,
perhaps the market is sending a “sober signal” and not a “foolish frenzy.”

Looking backwards, about the year 1997 government actions killed the reasons to own a diesel vehicle, but it took awhile for this to be apparent to vehicle users.