Title washing — the process of altering vehicle documents to remove unsavory details about a vehicle’s past from its title — is an increasing threat to the integrity and safety of the used-car industry in the United States.

According to a report released this week from researchers at Carfax, an estimated 800,000 used cars in the U.S. may be plagued by this issue, unbeknownst to their owners.

So what exactly can be covered up by this “title washing” practice?

The answer is daunting: pretty much anything that would probably make the average buyer walk away from a deal. Salvages. Flood damage. Rolled-back and non-functioning odometers. Many of these vehicles are repaired outside of the states where they’re sold, putting potential buyers looking for a deal at risk of financial and bodily harm.

The company claims the states hardest hit are New Jersey, North Carolina, Mississippi, California and Georgia — but that thousands of title washed vehicles could be in every state. More than 500 could be used as taxis.

Larry Gamache, Carfax’s communications director, believes looking into a vehicle’s history is one of the most key safety measures anyone looking to buy can make.

“Our research is clear evidence that title washing continues to fly under the consumer’s radar,” Gamache said. “These cars are sold mainly by perfect strangers who bank on you not taking the proper steps to protect yourself.”

On the dealer side, the responsibility is two-fold. Not only is it a good idea to find ways, such as providing a vehicle-history report, to assure wary used-vehicle buyers and maintain your reputation and integrity to your customer base, but it’s also the best way to protect your investments. Preventing title washed vehicles from being traded in or from going to auction is one key to saving money for everyone involved and potentially protecting the lives of those that drive your business.

For more information on Carfax and its services, visit their site here.