That cute little fox can save you some serious dough. Sometimes, the car dealer won't divulge every single detail about the car that you're looking at buying. The CARFAX will tell you if it's got any water damage, structural damage, if the odometer has ever had problems, or even if the airbags have ever been deployed. Now, if there are major problems, we don't suggest buying the car at all, but if it's something that just depreciates the car a bit, use it to your advantage and drop the price hard.