Imagine that you are looking for a used car on a popular site, such as Autotrader, Cars.com or Craigslist. You find exactly the one you want, with a very attractive price.

The ad has photos galore and even a link to a vehicle history report, which shows the car is in good condition and has a clean title. There’s an email address for inquiries, but no phone number, so you write for details. In the seller’s reply, he volunteers that the car is such a great deal because he’s a pilot and has had to relocate to the United Kingdom for a job with British Airways.

If you want the car, he explains, it’s easily done: Just wire the payment to an escrow company, which will hold the payment until you receive the car. He supplies a link to the escrow company’s website. There’s even a vehicle purchase protection program: If you look at the car and decide you don’t want it, you’ll be refunded.

What could go wrong? Plenty.

That scenario, with some variation, is an online car-shopping fraud that has played out more than 29,000 times since 2014. Would-be buyers have been swindled out of more than $54 million as of December 2017, according to the FBI’s Internet Crime Complaint Center.

The fake car ads use information cloned from actual listings. The sellers aren’t British Airways pilots, personal trainers, deployed Marines or grieving widows – these are just stories that have been used to further the scam. The escrow sites are clones of real sites, such as Escrow.com, or brands such as Edmunds that are known but don’t offer such services.

Dallas-based car-shipping service DAS, another company whose site has been faked by scammers, says many buyers aren’t aware they’ve been taken until they ask DAS for their delivery date.

“For the past several years, we’ve received about three calls per week like this,” DAS notes in its site’s fraud warning. “About a third of the people calling have already paid.”

The criminals behind the schemes have technical skills that are good enough to clone ads and create functional-looking websites.

And shoppers are already very comfortable with online buying, even for expensive products. An NPR/Marist poll this month found that 27 percent of shoppers had bought an item online with a price tag of $1,000 or more. Purchasing a car, sight unseen, from a stranger might not seem risky for some buyers. Criminals count on that faith in the legitimacy of online transactions.

The FBI and sites that are combating the scams, including Autotrader, Escrow.com, eBay Motors and Edmunds, offer these tips to avoid online car-buying fraud:

n Check the car’s real value with an online car valuation tool from Edmunds, Kelley Blue Book or NADAguides. If the price is too low, that’s a tip-off.

-- Avoid sellers who refuse to talk by phone, meet in person or let you physically inspect the vehicle before the purchase.

-- Be wary if a seller insists on using a particular online escrow company. It’s likely an attempt to steer you toward a fraudulent site.

-- Check any shopping or escrow site’s URL carefully. The company’s name and its domain (usually .com, as in Autotrader.com or Edmunds.com) should appear at the end of the URL or just before any forward slash. A fake Edmunds domain, for example, would be: www.edmunds.com.us.info-vehicle.com.

-- Don’t rely on any site link the seller supplies. Enter the company’s name in a web browser yourself, visit the site, and see if it actually provides the services the seller says it does.

-- Be careful if you’re offered a vehicle protection program. eBay Motors has such a program, but only for transactions that take place on the eBay Motors website. If you’re shopping elsewhere and the seller says eBay is supplying that protection, it’s a fraud.

-- Ensure that any escrow company you use is properly licensed. In California, for example, there is only one licensed online escrow company whose services are available to the general public: Escrow.com.

-- Don’t give out your financial or personal information, such as a credit card number or bank account information, until you verify that the online escrow company you’re using is legitimate.

-- Stay far away if the seller wants some unusual form of payment, such as gift cards, iTunes cards, or money sent via Western Union.

If you think you’ve been the victim of online car-buying fraud, contact your bank immediately to see if it can reverse the fund transfer.

Then file a report with the FBI’s Internet Crime Complaint Center and the Federal Trade Commission’s Complaint Assistant.

Edmunds says

Be vigilant when you’re shopping online for private-party cars. Scammers are sophisticated and highly motivated to get your money.

Carroll Lachnit is a senior consumer advice editor at Edmunds. Twitter: @clachnit.