The Sorry State of Used-Car Regulations

Van Alst says that most states aren't very effective at protecting used-car buyers from the myriad ways they can be swindled. "Most existing used-car lemon laws are so limited in scope — the number of days the car is covered and the allowable mileage — that the consumer may not experience the problem or won't have a chance to act on the problem in that time period," he said.

For example, Arizona law covers a used car only if a major component breaks within 15 days or 500 miles of its purchase — whichever comes first. For new cars, though, those terms extend to two years or 24,000 miles.

By contrast, many European consumers have stronger protections. In France, for example, a car buyer may cancel the transaction up to seven days after the sale. And a 1999 European Union directive allows consumers to seek redress for any problem that makes a vehicle unfit to drive for a full two years after the purchase.

As is always the case when buying a car, the only way to fully protect yourself is to come armed with information. Many consumer advocacy sites, such as The Center for Auto Safety, discuss new car lemon laws in detail, but obtaining information on used-car laws is trickier. We found Car Lemon (an attorney referral site) and Autopedia's Lemon Law Information Page to have the broadest information on states' used-vehicle lemon laws.