Transcript for How Do Flood-Damaged Cars Get on the Road?
We all know that buyer beware at first rule when shopping for a used car. In the wake of hurricane sandy there's a growing chance that car up for sale has been flooded. The prices are low but those cars may be too dangerous to drive. Bill weir found some people still willing to sell those cars despite the risk. Reporter: Just look at'em all. Flood cars as far as the eyes can see, filling the runways of an abandoned airport after super storm sandy and each one a potential highway hazard. They literally rot from the inside out. Days, weeks or months down the road parts are going to fail. Reporter: When makes it worrisome when you see that packed runway empty and this demonstration by the folks at used car, car fax. They make it look brand new after a five hour makeover and they estimate 100,000 sandy flooded cars are back on the road. This should have been sold for parts but we found it up for sale on this lot for $20,000. To investigate how, we bought it and held a reunion with former owner, mike kennedy. She was tuunder water for two days. Reporter: He watched sea water swallow his truck. The tools are still here. They are no longer functional because that was rusted shut. That water was up to here. The front seats don't work. I can't imagine what else doesn't work. These guys will. They're jersey shore mechanics. They know a flood vehicle when they see one. That's definitely water driven, no doubt about it. That's like fine silt. This thing might catch fire. If an air bag blows up on you you could catch. Would you put your family in that? Not in a million years or drive this truck out of here. Reporter: That truck was sold with a clean title so we took her down to the gates of a major insurance company to find out why but the lesson here is it may cost a few bucks up front to have a mechanic look at a used car but it could save you a lot of headaches. You can see more of bill's story tonight on abc's "the lookout" beginning at 10:00 eastern.
This transcript has been automatically generated and may not be 100% accurate.