If an offer sounds too good to be true, trust your instincts and leave it alone. And that goes double for any used car deal you read about online.

Car troubles --including misrepresentations in ads, faulty repairs and scams involving used car sales — are among the top complaints made to state and local consumer protection agencies, according to a survey by the Consumer Federation of America and the North American Consumer Protection Investigators.

USA TODAY reports that based on data provided by the FBI, the Internet Crime Complaint Center has received 1,685 auto-auction fraud complaints with a reported loss of $4.9 million this year through July 31. In all of 2011, the Internet Crime Complaint Center received 4,066 auto-auction fraud complaints with $8.3 million in reported losses.

Scammers are able to pull consumers in because many of their schemes give the appearance of being consumer-friendly and may even offer some semblance of consumer protection. USA TODAY says that in Eastern Michigan, the Better Business Bureau is warning consumers about criminals who hijack online ads to "sell" vehicles that they do not own and have no intention of delivering.

"Often, a good-looking car is advertised at an amazing price. The BBB notes that some type of "buyer protection plan" can be offered, but it's a scam, too," writes columnist Susan Tompor.

Jack Christin Jr., associate general counsel for eBay Motors in San Jose, said consumers should watch for any used car sale that starts on Craigslist or elsewhere — but then the seller supposedly moves the transaction to another website.

Christin also said that consumers need verifiable evidence that confirms the seller is the actual owner of the vehicle. Tompor noted that given the nature of the internet and online information, it's easy to show photos of a car online or via e-mail that you don't own.

These are some of the 'red flags' to watch for:

The con artist in a used-car scam may refuse to meet the buyer in person or even allow a vehicle inspection — claiming they're moving soon or they need to rush the sale.

Don't get caught up in a long sob story; (i.e., the seller may claim he has to sacrifice the vehicle for fast cash because his/her spouse or child needs a life-saving operation...)

Do not use a money transfer service, such as Western Union, to pay a stranger for a used car or other item. Such services are convenient but best used to send money to people you know.

Always look for transparency and third-party verification of the facts and the transaction. If you have doubts, walk away. And if you think you've been ripped off, contact your state's Attorney General's office immediately. Every state AG fields consumer autmotive complaints and they may be able to rectify the problem you bring them, or, at least help prevent it from happening to someone else.