One of the biggest reasons people buy used cars instead of new cars is to save money, as used cars are priced significantly lower. Other reasons include the ability to purchase a specific make and model of car, avoiding various fees and not having to worry about inevitable damage.
Cars depreciate at a rate much faster than many other big ticket purchases, such as boats or homes, which means that the resale value drops dramatically immediately after the car is purchased. As such, used cars cost in some cases thousands of dollars less than the same make and model new. This huge price gap translates into significant savings for many car buyers. Any damage a car receives also causes its value to drop, so many people buy used cars to avoid the emotional pain of knowing that an accident or scrape has reduced a car's value.
Another reason one might choose to purchase used cars is because she is looking for a very particular car, such as a classic car. If a car is no longer manufactured, it becomes incredibly difficult to find it new, so buying it used becomes the only option. Also, many older models of cars offer certain features that one may need, but are no longer included in newer models, such as a cassette tape player.