By definition, any car with more miles on the odometer than it takes to move or road test it is a used car. When you buy one, you take on certain risks - but you can finally get some much-needed and overdue protection from Uncle Sam, advises Changing Times, the Kiplinger magazine.

All used cars sold by a dealer must have a "Buyers Guide" affixed to the window. It's the federal government's way of making used-car salespeople honor their commitments. For the most part, the Buyers Guide sets down in writing the warranty conditions that cover the car or spells out in plain language that the car is being sold "as is."If a used car is still covered by the manufacturer's original warranty, be sure to check the date the warranty became effective. In the "systems covered" section of the guide, the dealer must spell out the terms of the warranty. Otherwise the dealer's full or limited warranty will appear there. You should find the length of the warranty; deductibles, if any; the percentage of the repair cost the dealer or manufacturer will pay; and the specific parts and systems - frame, body, brakes - that are covered.

About half of all used cars are sold as is, without an express or implied warranty. The "as is" box at the top of the guide must be checked. If you buy such a car, you must pay for repairs. Connecticut, Kansas, Maine, Maryland, Massachusetts, Minnesota, Mississippi, New York, Rhode Island, Vermont, West Virginia and the District of Columbia restrict "as is" sales.