The buyer's guides found in newsagents are based on the same trade guides that dealers use, although they take a broader approach to account for variations in condition, mileage and age.
Most will include some adjustment calculation to work out the approximate value of a car if its mileage is particularly high or low.
These guides give you a good base figure to work from, but it's best to check out other sources to gain a more rounded idea of your car's value.
Many guides do not include cars more than 10 years old, so check your car is included before buying a guide.
Also, the prices in printed guides are quite general. Your mint condition, bubble-wrapped-from-new RS Turbo may not be given as favourable price as you'd get from a fellow enthusiast, for example.
