Hundreds of thousands of storm-damaged cars are poised to flood the used-vehicle market following Hurricane Harvey, and now Hurricane Irma is threatening to place even more consumers at risk of unknowingly buying a wrecked ride.

With as many as 1 million vehicles in Texas damaged or destroyed by Harvey's furious floods — and Irma barreling toward Florida — analysts are warning Americans to check vehicle history reports and inspect used cars carefully before buying.

Vehicle history report company Carfax said about half of cars damaged by floods return to the road.

That places hundreds of thousands of Americans at risk of buying what the auto industry considers "flood cars," which was a common problem following Hurricane Katrina and other storms.

"They're getting duped out of thousands of dollars with a vehicle that's literally rotting from the inside out," Carfax spokesman Christopher Basso said.

CarFax estimates that there are about 325,000 flood-damaged cars on the road today from past storms, spread among all states.

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Three common ways this happens:

Auctions. After an insurance company slaps a flood or salvage title on a vehicle, it gets auctioned off legally and then salvaged and cleaned by a buyer who puts it back up for sale to consumers.

"It happens all the time — anytime there's a flood," Autotrader.com analyst Michelle Krebs said.

For sale by owner. Owners with minimal insurance coverage rigorously scrub the vehicle themselves, possibly replacing carpet or upholstery, and sell it to an unsuspecting buyer. Sellers often move the vehicles to other states to escape scrutiny, putting anyone at risk of buying a damaged ride.

Forged or bogus documentation. Sellers tamper with title records or other documentation to trick buyers into believing the cars are in good condition.

Hurricane Harvey victims are especially at risk of buying flood cars because they need to find transportation immediately if they don't have access to free rental cars through insurance.

But AAA car-buying expert David Bennett advised consumers to approach the process with caution.

"Try not to rush into a decision and make sure you're going to be buying a car that fits your needs," he said.

Here are tips on how to avoid buying a flood car:

Check the vehicle history report. After insurers cover flood damage on a vehicle, the vehicle history report will notate its status as a salvaged car. AAA's Bennett recommended that owners check Carfax for those records.

Carfax has opened up its database — which draws information from more than 100,000 sources, including insurers and mechanics — for free flood-history checks following Harvey at Carfax.com/flood.

Ask a mechanic to conduct a pre-purchase inspection.

"It's really that one-two punch of the vehicle history information and the trained eye of a mechanic to best protect you from buying one of these water-logged wrecks," Basso said.

Use your nose. Check closely for musty smells inside the vehicle, which could indicate the past presence of moisture.

"The smell test basically indicates that water has been in there," Bennett said.

Pull back the carpet to check for signs of water or mud. Walk away if you see new carpeting or upholstery.

Make sure power locks and windows work. If they don't, it could indicate electrical damage.

Check headlights and taillights for water, which may indicate past submersion.

Look for corrosion anywhere on the vehicle, although it may take time for rust to show up.

Don't take the seller's word for it. "We encourage people to take the car for a full test drive," Basso said.

Follow USA TODAY reporter Nathan Bomey on Twitter @NathanBomey.