1. Age and Mileage: Generally, the older a car is and the higher its mileage, the lower its value. Cars with lower mileage and in good condition are usually more desirable and may have a higher value.

2. Vehicle Condition: The overall condition of the car, including its exterior, interior, engine, and mechanical components, plays a significant role in determining its value.

3. Market Demand: The demand for a particular make and model in the used car market can influence its value. Popular cars with high demand may retain their value better than less sought-after models.

4. Vehicle History: A well-maintained car with a clean history, free from accidents and major repairs, may have a higher value compared to a car with a history of accidents or extensive repairs.

5. Features and Options: Cars equipped with additional features and options, such as advanced technology, safety features, premium audio systems, and leather seats, may have a higher value.

6. Location: The geographical location can impact a car's value. Prices may vary based on regional demand, local market conditions, and even weather-related factors.

7. Service Records: A documented service history that demonstrates regular maintenance and care can positively affect a car's value.

8. Market Trends: General trends in the used car market can influence values. For example, during periods of high demand for used cars, prices may be higher.

9. Economic Factors: The overall economic climate, including factors like inflation and interest rates, can affect used car values.

To determine the true value of a used car, you can use various resources, including online valuation tools, such as Kelley Blue Book (KBB) or Edmunds, which provide estimated values based on the car's make, model, year, mileage, and condition. Additionally, you can compare similar cars for sale in your local market to get a sense of their prices and how they align with the car you are considering.

Ultimately, the true value of a used car is the price at which a willing buyer and a willing seller agree to transact in the current market conditions. It's essential to research, gather information, and potentially get the car inspected by a qualified mechanic before finalizing any purchase to ensure you are paying a fair price.