Cars are big-ticket items, and there are many ways for fraudsters to bilk unsuspecting victims. The rise of Internet commerce has vastly expanded the ways to separate a mark from his money, and has effectively made it a global business.

Consumer complaints rose 25 per cent in 2010 and a complaint is filed every 90 minutes, according to a Consumer Reports article citing FBI stats. Regarding auto-related complaints, every hour a car buyer loses more than $1,000.

The online car sales company Cars.com employs a fraud team to help weed out the most fraudulent ads on its website.

"The number one piece of advice we can give for buyers and sellers is to listen to that inner voice that says, ‘This is too good to be true,'" advises the site's spokesperson, Ron Hall, "because we've found that it always, always is."

While it may seem like a no-brainer, never purchase a car or send money for a vehicle without seeing it first. "You'd be surprised at how many people do that," he says.

The Cars.com fraud team put together this list of the most common scams in auto sales.

Keep in mind the schemes and tactics that follow are not mutually exclusive - some scammers take pages from numerous playbooks. Click on ahead to see them all.

Cheque Scam
Scams involving cheques (i.e. personal, cashier's, third-party checks, money order) take many forms. In a typical example, a thief posing as a car buyer "accidentally" sends a cheque made out for an amount higher than the selling price of the vehicle and requests that the seller deposit the cheque and return the difference via a wiring service (Money Gram, Western Union, etc.). After the seller has wired the money, he or she learns the buyer's cheque is worthless, and the thief disappears with the seller's money.

The Snopes page dedicated to cheque scams (including the famous strain originating from Nigeria) recommends waiting three weeks for any sizable cheque to fully clear. Even if it looks like the funds are available in the bank account before that time, cheques could still turn out to be counterfeit.

Sympathy Scam
Preying on the sympathy of a mark is one of the oldest tricks in the book. In a common auto scam, a thief posing as a seller supplies a sad story to a potential buyer about why he or she needs to sell the car quickly (he or she is about to be deployed on active military duty or is dealing with a divorce, illness, the death of a loved one, etc.). The sob story explains why the car's asking price is so much lower than its current market value, and puts pressure on the buyer to make a quick decision. Buyers who fall victim to this scheme can end up with a lemon, or with no car at all.

Shipping Scam
In the shipping scam, a thief posing as a seller requests a deposit on a vehicle and promises to ship the vehicle to the potential buyer for personal inspection within a set number of business days. Typically thieves will tell prospective buyers a third-party shipping company will be in contact with the buyer to ship the car after the deposit is sent via wire service. Scammers often use forged or copied websites to appear legitimate. An investigation by the BBC revealed criminal gangs are often the perpetrators of shipping scams and other types of auto fraud.

Purchase Protection Plan Scam
In this scheme, the con artist pushes a protection plan for the transaction on a fake website. The potential buyer is encouraged to send a deposit or the full amount of the vehicle. The protection plan states that if the potential buyer does not receive the vehicle, he or she will be reimbursed for the total amount of the transaction invoiced. Common tools for this scam are websites customers are comfortable with such as EBay, Edmunds, Google Checkout, Cars.com and NADA Guides. This is another scheme that uses bogus websites, including the recent example of Kelley Blue Book.

Photo Scam
The photo scam happens when a vehicle is listed online, with the text giving a normal market rate of, say, $13,000, while the photo accompanying the ad shows a price written on it of $4,000. The thief tells the potential buyer the price of the vehicle is $4,000, saying it was reduced for some reason designed to elicit sympathy (e.g., a recent layoff or death in the family). The victim pays the reduced rate thinking it's a bargain, but then never receives the vehicle.

Cars.com uses automatic filters to screen the text of ads, looking for cars that are priced too far below market value. Rock bottom prices are "almost always" a scam, according to the website's fraud squad, so these listings get booted out of the system. Filters may not pick up text in a photo, however, so Cars.com employs a team to review a high percentage of the "sell-it-yourself" ads. Still, some slip through, so be wary of prices that look too good to be true.

Location Scam
Another shady practice in car sales occurs when a potential buyer finds an ad for a vehicle that is for sale locally. After contact is made, the scammer tells the buyer the car is located someplace other than where it was advertised, but it can be shipped anywhere in the world...for a fee, of course. The victim pays the money but never receives the car, and the thief gets away with the "fee."

Sight Unseen Scam
With this maneuver, fraudulent sellers make up a story about why they aren't able to physically show the vehicle due to unforeseen circumstances (e.g., they're travelling for work, or they're away on active military duty, etc.). The sellers request that payment be sent in full and advises that the title will be sent when the vehicle is shipped. Now is a good time to reiterate the advice of the experts at Cars.com: Never purchase a car or send money for a vehicle without seeing it first.

Also, keep in mind that even though a vehicle may look OK, the background check should go further. Have a licensed mechanic check the car for damage or defects, and to ensure it's not a flooded car.

Wire Service Scam
Wire services such as Western Union and Money Gram are a favorite with scammers because financial transactions can be conducted anonymously and the recipient doesn't have to offer proof of any service rendered or goods exchanged in order to collect the cash. A wire service scam in auto sales involves a potential buyer receiving an invoice stating that wire services can be used to complete transactions online. The buyer is advised this is the common payment method used by the site. If the supposed car seller doesn't recommend using a legitimate escrow service, such as Escrow.com, to complete the transaction, it's probably best to carry on the car search elsewhere.

Phone Scam
In an auto sales phone scam, the thief provides a contact phone number for potential buyers to use to inquire about the vehicle for sale. With Cars.com, for example, a field for a phone number must be completed, so scammers might enter a fax line, or a number they've just made up. Then the potential buyer is forced to email, and the fraudulent seller will inform the buyer that they prefer to do business over email anyway, and the scam proceeds from there.