Questions to Ask When Buying a Used Car: Buying a used car cab be smart investment when you need a replacement vehicle. While new car purchases tend to increase with a rising economy, used cars can provide a great alternative as long as you know how to shop for one. You get the most bang for buck with a used car. While this provides an opportunity to live more economically, a used car, by definition, has issues from regular wear and tear. Therefore, it is important to avoid making these costly mistakes when you are in the market for a second-hand car.