When you're looking to buy a used car, you probably already know that it's not going to be in perfect condition. However, what you might not consider is that there's a pretty good chance the used car has been in an accident. A recent CarGurus report found that about one in six used car listings (16 percent) in the U.S. had an accident on their vehicle history reports. This includes about 8 percent of newer models that were made between 2009 and 2011. An accident history can reduce the value of a car between 3 and 12 percent, so a lower price than you expect could be a red flag.

"There is great savings potential in buying a used car, but there's also the potential to get burned if you don't do your homework," said Langley Steinert, founder and CEO of CarGurus. "A minor accident or prior fleet ownership does not have to be a deal breaker, but it is information you absolutely need to know as you consider the purchase and the price."

You don't have to worry about buying a car with a mysterious background when you shop at New Jersey State Auto Auction. Every model on the lot comes with a CARFAX vehicle history report, so you will know right away if the auto you want has been in accidents in the past.

For added assurance, it can be a good idea to have an independent mechanic inspect the car you want before you buy. This typically costs between $75 and $150, and the expert may be able to spot an issue that you might overlook, such as a worn part that will soon need to be replaced. This can help you make a more informed decision, and it might even give you leverage when negotiating prices with the dealer.