Very well put Mr. Peters....Unfortunatly as the market goes down and car prices go up, the propensity for people to "embellish" (not refering to the Chevelle in the post, nor the delaer in question...) about any given car will increase. While I agree that there are certian cars out there that have quirks about them, unless they are fully documented (ie: original period photos for instance in the case of a no smog LS6) then Mr. Gibson's 90/10 rule (guess I can call it that...) should be used if undergoing a full frame off (with top dollar being a goal). That is if 90% of the cars would have had it, then add it since it was an obvious defect...
As far as the outright lying to misrepresent cars goes...it has always been my opinion (we all know what they are like...) that a dealer has an even higher ethical standard to uphold than a private individual...I know in reality it doesn't make a difference to the poor SOB on the other end, but a dealer is assuming some liability for product knowledge that the individual doesn't have....