Cars under 10 years old with under 100,000 miles may be eligible for a dealer trade-in. If you plan to trade in your car, negotiate this separately from your new car purchase price. Older cars or those with more miles would fair better via private sale. Of course, you can always keep your old car, especially if you have teens nearing the age of learning to drive. If you plan to trade in or sell your old car, ask the dealer if they can beat the appraisals you’ve gotten for its value. Learn more about what questions to ask when buying a new car.