Why it's on the list: Repairs; Insurance; Depreciation; FuelThe Mazda RX-8, one of two cars on the list from the automaker, has high costs in four of the six categories, the first being depreciation. Although it doesn't lose its value as fast as other cars on the list, the fact that it loses such a significant amount is something to take note of. Combine that with the cost to insure the vehicle and you're looking at a good amount of cash being taken out of your bank account that you won't see again, even if you eventually sell it. If the insurance costs don't get to you, the repairs will. Fixing this car takes some serious money, so it's best to take care of it. The worst thing about this car, and the thing that will guzzle the majority of your money is the fuel economy. Talk about a gas guzzler. After hearing all this, it seems like only someone who's made of money will be able to afford this used car.