Regardless of whether you’re looking to trade in a used car, buy a new vehicle, or sell one with the hopes of getting some of your investment back, it’s important to understand how you can calculate the value of your used car in order to get the best possible deal. While the trade-in or selling price of used cars will generally come down to what a seller and buyer agree upon, there are numerous ways to determine the full market value of a pre-owned vehicle. For example, one of the most common methods is to make use of NADA used car values.