Nothing depreciates in value like a car. Buy a certified pre-owned from the actual dealer and you usually get an extended warranty, etc so you don't have to worry about buying a lemon from some random dude on craigslist. Downside is that someone else has driven it and the options are more limited. But you'll save a ton of money, especially if your aunt doesn't drive a lot. And it sounds like she won't now that she's retired.