Rearview mirror advisors

What do "rearview mirrow advisors" mean?

Don't know the context but it could either refer to the ubiquitous phrase found on U.S. car mirrors, "Objects in mirror are closer than they appear", or it could be a humorous re-phrasing of "back seat drivers".

Knowing that I'm taking an awful risk by making a guess and asking a question here - given the response last time I did this... Seeing this question was asked at the same time as those other two stockmarket questions, is it a stockmarket term? eg. People who advise after the fact perhaps?