Pretty much every website for car buying today has some sort of "Fair Market Price" tool. I see graphs, charts, and calculations of all kind that all produce differing results but have one very common factor: No one pricing tool has been declared accurate by even a majority of dealers. To me, it's impossible to have a computer determine value in a free market because in a free market value can only be determined by what each individual person is willing to pay. That being said where do these websites get all of their data? I know Truecar get's access to their dealers' actual figures but outside of that how do all of these other websites declare what cars are being sold for? Or are they simply taking listing prices and counting those as actual sales?