In general, buying from a dealer is a safer option because you are dealing with an institution, which means you are better protected by law. The Federal Trade Commission requires dealers to post a Buyer's Guide in the window of each used car or truck on their lot. This Guide specifies whether the vehicle is being sold "as is" or with a warranty, and what percentage of repair costs a dealer will pay under the warranty. Keep in mind that private sellers generally have less responsibility than dealers for defects or other problems. FTC rules do not apply to private-party sales.

Expect to pay higher prices at a dealer than if you buy from an individual. Many dealers inspect their cars and provide an inspection report with each car. However, this is no substitute for your own inspection. Some dealers provide limited warranties, and most sell extended warranties. Watch out for dealer warranties that are "powertrain" warranties only, and not "bumper-to-bumper" full-coverage warranties. It's best to compare warranties from multiple sources.

Some dealers provide "certified" cars. This generally means that the cars have had a more thorough inspection and come with a limited warranty. Prices for certified cars are generally higher. Be sure to get a list of what was inspected and what is covered under the warranty.

Purchasing a car from a private seller could save you money, but there are risks. The car could be stolen, damaged or still under a finance agreement. If a private seller lies to you about the condition of the vehicle, you may sue the individual if you have evidence and you can find him. An individual is very unlikely to give a written warranty.