David: At the DMV the other day, I met a woman who bought a car over eBay. Was she crazy? Is there any way this is a safe thing to do?

Michael: A friend has bought two late-model Cadillacs via eBay in the past three years. He prefers buying one- or two-year old cars so he doesn't lose the money one loses to depreciation by buying a brand-new car off the lot. Several other people I know have both bought and sold used cars online, including classics. Of the dozen or so eBay vehicle sales involving people I know, no one has come away unhappy.

The first thing you want to do is check the value of the vehicle as it is described (based on condition, mileage, etc.) You can check the Kelly Blue Book value of the car or truck at http://www.kbb.com. Ignore the dealer prices; these are inflated. And don't stop there. Look at what similar vehicles are selling for in your area (again, ignore dealer prices), and on eBay. These sources will help you determine what the car is realistically worth to you.

It is important to make sure the car is as described. Ask the seller everything you need to know about the car. And look into the car's history, using one of the online services like CarFax (at http://www.carfax.com). eBay recommends using its AutoCheck service (at http://pages.motors.ebay.com/services/vehicle_history_report.html).

If you find something in the car's history that the seller didn't disclose (collision repair, water damage, etc.), don't bid. If you've already bid, you can cancel your bid.

Make sure the car has a clear title, and if you win an automobile auction tell the seller that the sale is conditional, based on your physical inspection and approval of the vehicle (or inspection by a third party you designate). Don't make a deposit; sellers who demand a non-refundable deposit may have something to hide. Maybe they fear you won't like the car and back out of the deal unless they get some of your money up front. Sellers have no reason to require a deposit or "good faith money," as they aren't doing anything for it.

If a seller demands a deposit to "hold" the car, tell him to go ahead and sell it to someone else if he can't wait for you to examine the car. (This will usually end any demands, as you will probably be the only buyer.)

Beware of a seller who tries to rush you through the buying process. Here again, the seller may have something to hide.

As for delivery, you can use an auto transport service, or pay someone to fly out and pick up your car. But most eBay car buyers pick up their car themselves, flying or having someone drive them to the seller's location.

David: How can you make absolutely sure you're going to be safe making a huge purchase like a car on eBay?

Michael: For any big-ticket item, whether it's an automobile, an autograph, or a diamond ring, I recommend that you examine the item before buying. Make the sale conditional on your approval, or that of an expert who will examine the item for you.

You may want to hire an appraisal service to validate the authenticity and actual value of certain kinds of items (collectibles and jewelry, for instance).