Let the buyer beware. The responsibility to check a used car when buying it is ultimately yours. In my opinion, it is likely that the dealer did not know the non-stock parts were there.
When I trade my cars into the Ford dealer, the first question from the dealer is typically, "Are there any modifications made to the car?" Modified cars do not sell well, so dealers want them to be stock.
Bobby B, a patriotic Long Island Senior Citizen who drives a 2011 5.0 Premium GT Coupe, all black, 6-speed MT82, 3.55:1 differential, Bama 87S Tune, 18" diameter wheels, Pirelli P-Zeros, Comfort & Security Packages, spoiler delete.
God, please bless the USA