Edmunds, Kelley Blue Book and NADA figure these values on "average" values based on used sales, trade ins, dealer auctions,then the compile the data for each model and year. they alter the value based on mileage, options and condition,and sometimes based on region. cars at the bottom of the list tend to be lower priced, higher volume cars that get "used" (daily commuters, grocery go-getters, junior's first car, etc..) so when it's time to sell or trade , they have their share of bruises, bumps, cigarrette burns ,and so on. the cars on the top of the list are usually exotic, low production cars that are "babied" (not driven in snow , left in parking lots, smoked in , etc) most people that can afford one of these has a second car, or a company car that does all the dirty work. so it really does not say much to compare residual value in a Porsche 911 and a Neon or an Intrepid, it's liks comparing apples to oranges.