DETROIT — In the days since Superstorm Sandy, an alarming prediction has flashed across the Internet: Hundreds of thousands of flood-damaged vehicles will inundate the nation’s used-car market, and buyers might not be told which cars have been marred.

Not true, according to insurance-claims data reviewed by The Associated Press. The actual number of affected vehicles is far smaller, and some of those cars will be repaired and kept by their owners. The dire predictions are being spread by a company that sells vehicle title and repair histories and by the largest group representing American car dealers.