How does NADA and kelly blue book come up with their car price recommendations?

Both companies use thier many years of car appraisal experience to determine prices.

It starts with the value of the car when it was new and takes into account market forces that are in play at the time.

Cars with good fuel efficiency are in demand right now, so they might fetch higher prices.

The depreciation of a car's value is calculated based on previous model years, the quality of the car and the number of cars on the used car market.

Common cars that were bought in bulk for rental company fleets command lower prices because the used car market is virtually flooded with them.

High-quality cars, or cars that were made in limited quantities, receive a higher value.

Cars known to have long-term mechanical problems will depreciate to a greater extent.

Optional equipment, mileage, and the overall condition of the car will also affect the price.