CHICAGO (CBS) — Buyer beware! Flood damaged cars are showing up in want ads, on Craigslist and as potential trade-ins to dealers who really want nothing to do with them.

The Chicago Automobile Trade Association, the Chicago area’s major new-car dealer group and sponsor of the Chicago Auto Show, has issued an alert to its members warning of the flood of damaged cars likely to be brought in.

At Arlington Heights Ford, owner John Guido said Friday that he had five flood-damaged cars in the shop, three of which were repairable. Guido said in two of the cases, the cars were deemed “totaled” by the owner’s insurance company but the owner wanted to keep the car anyhow.

Down the line, though, Guido said the cars could be nothing but trouble, and has advice for those seeing a like-new used car on the market for a ridiculously low price: do your homework.

He said there are some foolproof ways to tell that a car has been inundated in a flood that may not be obvious to potential buyers but can be spotted immediately by mechanics.

He said it could be as simple as peeling back the carpet in the car to see if the floor beneath it remains damp, or checking to see if there are leaves, other debris or water in the spare tire well. He said to check to see if sensors such as the check engine or ABS lights trip on and off without reason — a sign that the fuse box was inundated.

Guido said other telltale signs are rusty screws inside of the car and rusty brake calipers. But he said the easiest test is to simply turn on the engine, turn the heat up to high, and direct it to the floor. He said if the car’s windows steam up, the car has been flooded.

Guido’s nephew and partner, Tony Guido, said that the car that is older but looks “like new” could signal a problem.

“An older car or (one that is) recently-detailed, shampooed or cleaned under the hood so that it looks like it’s brand new are some indicators to look at also,” he said. “A lot of people don’t keep their cars as clean as that over the years.”

The younger Guido said that a musty smell inside the car is also a dead giveaway.

“You start smelling water damage over a period of time,” he said. “Water doesn’t really come out of the crevices.”

The Guidos say not all flooded cars are as bad. A car in which the water barely lapped over the lip at the doors is not as bad off as one that stood in water up to the windows, they said. Insurance companies may opt to repair cars that suffered relatively minor flood damage, but John Guido said those they were inundated or floated are not likely to be deemed repairable by insurers. Yet, he said, some are.

If in doubt, the Guidos said, take the car to a mechanic you trust, or to a dealership. He said it may cost a few bucks to put the car up on a hoist to be checked, but said it’s worth the headaches you can avoid.

“Let them pull up the carpet, let them look in the trunk where the spare tires are and see if there’s any evidence,” he said.

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