Acquiring a new vehicle can be exciting, yet daunting. That challenge is magnified if you decide to purchase a car on the Internet.

While the Internet often helps make buying a vehicle easy and cost-effective, it's not without risk.

"You have to go under the assumption that there's no safety net. ... I hear about fraud every day," says Jeff Ostroff, founder and editor of the consumer Web site CarBuyingTips.com.

The best precautions boil down to sound judgment and due diligence to avoid getting snagged in a bad situation in the first place.

"Just because you're buying a car online doesn't mean common sense goes out the window," says Chris Jacobs, an auto pro at eBay Motors.

"Like any purchase, make sure to ask as many questions as possible and know as much about the car as you can before agreeing to payment."

Check out the seller
It's a common fear when shopping online: You find the car of your dreams and send off a deposit.

Then, the seller vanishes.

The secret to success when shopping for a car online is doing business with someone who is reputable, whether it's an automobile dealership or an individual via the Web.

Once you see a vehicle you're interested in, e-mail the seller and ask to see the car in person.

It doesn't matter if you don't intend to follow through with a scouting trip -- the point of asking is to see if a seller turns you down or is eager to make time for you.

"If you get any resistance, it's a fraud," Ostroff says. "There's no vehicle for sale."

Asking other questions is a great way to get to know a seller better and weed out potential phonies.

For example, ask for additional photographs of the vehicle if you want a better view of the car's interior, trunk or other parts. If a seller doesn't answer you quickly or seems evasive, move on. It's not worth the risk, says Mitch Turck, a consultant at DealerDNA, an automotive e-commerce solutions provider in New York.

Meanwhile, take advantage of the Internet to get to know a seller in other ways. Read the feedback posted by customers who've done business with a seller in the past, a feature of eBay Motors and other sites.

Identifying reputable sellers is crucial. Once your hard-earned money leaves your hands, it may be impossible to track down an online thief and get your funds back.

Research your choice
When shopping online, your best protection is your own due diligence.

"Trust but verify," Ostroff says.

To get a full read on a vehicle's history and determine its overall condition, start with its vehicle identification number. The VIN identifies the vehicle and is the key to unlocking its history.

Once you get the VIN, order a report on the vehicle from companies like CARFAX and AutoCheck that will reveal important details about the car.

Such details include whether the car has been in an accident or a flood, if the airbag has been deployed, previous odometer readings (important to be sure it hasn't been rolled back) and even if the car's been resalvaged.

Then, get a mechanic to look at the car on your behalf. Independent companies like SGS Automotive Services can inspect most cars for roughly $100, and you can hire an inspector to eyeball the car, even if the automobile is located in a city far from where you live.

It should go without saying that any seller who balks at an inspection is probably unreliable -- and so is their car. In that case, it's probably smartest to close the browser window on the seller and search for a different ride.

Vehicles sold "as is" pose the greatest risk to buyers because when you purchase them, you're agreeing to take on any problems with no warrantee to protect you.

For that reason, expect to "run up against a brick wall" if you try to recoup your money from an "as is" seller, be it an individual or dealer, says Ostroff.

Don't assume dealers are better
Often, buyers feel more comfortable purchasing cars online from established dealers than from an individual.

However, such faith may go unrewarded, Turck says.

Even with an established dealer, you could well lose your deposit or lose out on the car of your dreams.

"A deposit should give you the so-called first right of refusal to change your mind, recoup your cash, and walk away from the deal, but that's not how it works," Turck says. "If a guy walks in and buys the car between the time you made a deposit and you getting there to pick the car up, it can be sold."

What's more, there's no guarantee your deposit will be refundable, Turck says. In some cases, dealerships "will try to keep the money" or get you to purchase a different car.

Sometimes, a trail of e-mails can help bolster your claim. E-mails are not contracts -- for that, you'll need a final financial contract. However, e-mails can act like a buyer's order, the document that spells out the car you intend to buy and agreed-on price.

As a result, e-mails give you more power to get a deposit back, says Turck.

When shopping with online dealers, listen to your head -- and your gut -- to avoid problems in the first place. As you would with any seller online, establish contact as quickly as possible and ask questions.

And remember that promises don't mean much.

"Anything that's promised over the phone should be considered useless," Turck says.

Play it safe when paying
When it comes time to make a deposit, play it safe. Never send a check or make a wire transfer. Your money will be irretrievable once a check has been cashed or a money order has been collected.

Instead, make payments over a secured browser -- look for a lock icon in the address bar and a URL that starts with "https." More importantly, pay with a credit card, which will protect you against fraud.

When Jennifer Dunn logged on to eBay Motors -- the nation's biggest automotive Web site -- to look for a used Chevy Tahoe, she found a truck listed by a Texas dealership.

Her husband, Neal, had reservations about buying online.

"My husband thought I was crazy," Dunn says. "He couldn't believe I was buying a car online. He was nervous."

However, Dunn reassured her husband by using a credit card for the purchase.

"I put down a $500 deposit using a credit card," she says. "I figured if anything happened, they'd fight for me, too."

Credit cards are typically your best defense when buying online.

Federal protections spelled out under the Fair Credit Billing Act limit your liability at $50 when cards are used to make unauthorized purchases. And some cards like Visa have zero-liability protection for cardholders.

If you don't get the vehicle promised -- either because a fraudulent seller stole your money or a dealer sold it to someone else -- you can turn to credit card companies to help get your money back.

At American Express, for example, customers who don't receive items they paid for can request a dispute resolution process simply by calling the company.

"If you use your card and don't get what was promised to you, then you should call a customer service agent right away and that representative will begin a process where you get temporary credit on your account," says American Express spokeswoman Monica Beaupre. "American Express will take responsibility in helping to resolve the dispute fairly."

PayPal is another safe payment option. Use it to draw money from a credit card and to make your deposit to a seller. The maximum you can spend using a PayPal account is $4,000 for one-time single transactions and up to $10,000 for PayPal members.

If you buy a vehicle on eBay Motors, you may also be protected up to $50,000 through its Vehicle Purchase Protection program, which is designed to shield buyers against certain losses due to some kinds of fraud, including if you pay for or make a deposit on a vehicle you never receive.

To qualify, you must complete your transaction on eBay Motors, however. Like anything else, there are terms and conditions and fine print, making precaution your best bet of all.

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