For most people, buying a used car is at best a journey into uncharted territory and at worst a trip into the lion's den. Self-protection should be a consumer's first priority, and for that reason, if you're planning on buying a used car in the Washington area, you should look first in Maryland.

The reason is a state law that, since 1971, has provided a used car buyer with more warranty protection than is available in Virginia or the District. In Maryland, a consumer buying a used car that is less than 6 years old and has less than 60,000 miles on the odometer automatically gets an implied warranty from the dealer that the car can be driven a reasonable length of time, based on such characteristics as age and condition.

That is in sharp contrast to the protection a consumer gets in District and Virginia, where a dealer isn't legally obligated for repairs that may be needed after the car is sold. In used-car jargon, that is called selling a car "as is." And, except for a few states such as Maryland, selling a car "as is" is the standard practice in the industry. But many consumers don't understand that buying a car that way leaves them with little recourse when something goes wrong.

A study by the Federal Trade Commission found that more than 36 percent of those surveyed thought the dealer would have to pay some or all of the costs if the car broke down within 25 days of an "as is" sale. In fact, the dealer doesn't have to pay anything. Some of the consumers who were questioned thought that any hidden defects would be covered by the dealers. They were wrong too.

Maryland Assistant Attorney General H. Robert Erwin Jr., chief of the consumer protection division, explains the "as is" distinction this way:

"Prior to the passage of the law, we had cases in Maryland where a consumer would buy a car that was two or three years old with 26,000 to 28,000 miles--and then two months later the engine would give out and there would be repairs of $1,000 or more. Under the old law before 1971 , the consumer who bought the car 'as is' wouldn't have a claim. But under the present law, he would have a claim under the implied warranty that the engine shouldn't give out after 26,000 to 28,000 miles--that the engine should last longer than that."

The consumer buying a used car "as is" in Virginia or the District has no implied warranty when the engine blows. Any claim is forfeited when the purchase papers are signed agreeing to accept the car "as is."

Because of the absence of implied warranty protection in the District and Virginia, anyone buying a car in either place should try to get an express warranty at the time of purchase.

"There is nothing beyond that--negotiating some type of warranty--that the consumer buying a used car can do in Virginia," said Mary Ann Shurtz, coordinator of the Northern Virginia Department of Agriculture and Consumer Services. The same is true in the District, officials said.

If you have bought a car in Maryland and something goes wrong with it that you think is covered by the warranty, the first step is to go the dealer. If the dealer won't make the repairs, the consumer can take the case to court. But the more practical approach is to contact the attorney general's office or the dealer licensing section of the Maryland Motor Vehicle Department.

"We would look at the facts of the case, talk to the dealer and decide if we agree with the consumer," Erwin said. "If we become involved, we can persuade the dealership to make some adjustment, if not full warranty coverage."

The FTC--which was defeated in its attempt to require auto dealers to disclose known defects to consumers buying used cars--has literature explaining the "as is" statement and other used car issues. To obtain that material, write Used Cars, Federal Trade Commission, Washington 20580