If you're buying a used car, be careful. You could be buying one that has been stolen, thanks to a new crime fad.

We are talking auto identity theft and it's all about stealing Vehicle Identification Numbers (VINs).

More than 225-thousand out of one-point-five million vehicles stolen each year are given cloned VIN numbers.

Carfax reports that VIN cloning has cost consumers and insurance companies four billion dollars over the past decade.

Here's how it works: Thieves copy VIN numbers of legal cars, then make new VIN plates for stolen cars. Your VIN, a 17-digit alpha-numeric code is sort of like the Social Security number for the car. State motor vehicle departments requre a vehicle identification number to register a vehicle. Add a faked title and cloned VIN to a stolen vehicle and you've got a sale that might look good, but it isn't.

The victims are hit on both sides -- the stolen number and the unsuspecting buyer of the cloned vehicle.

If you purchase a cloned car police will seize the property and you will lose the money you spent on it. Cloned cars turn up everywhere.

Police say you can protect yourself on the buyer's side by making sure you know the background of who is selling you a vehicle.

Getting a CarFax report on any potential purchase is also a good $15 investment. Don't forget to also check the StolenCarReports database to see if your vehicle has been stolen.

Thieves are less likely to steal and clone a car that will require them to replace all of the windows. For that reason it is worth the $20 investment to purchase a do-it-yourself VIN etch kit or find out when your local police can do this for you.