Your car dealer won't freely offer this information, but auto repairs are sometimes covered after the car warranty has expired. This is especially true for problems that began before the warranty expired. Your original receipts for all repairs you've had done are very important - especially for those done after the warranty period expired.

In fact, one of the best-kept secrets in the auto industry is informal warranties. When a manufacturer has the same problem with lots of new-model cars, regional sales offices and car dealers may be informed that the manufacturer will cover the cost of repair - beyond the standard warranty.

But don't expect manufacturers or dealers to publicize these warranties.

If you have a car problem that you think may be covered under one of these warranties, visit the Center for Auto Safety (or call 202/328-7700), an auto-complaint clearinghouse that tracks corporate memoranda, bulletins to regional offices and dealers, and car-owner complaints. Tell the Center your car's year, model and problem, and they will send you information on any components that are likely to be covered under an informal warranty.

If your problem appears to be covered, talk to the dealer's service manager and ask for it to be repaired. If he or she won't fix the problem, contact the factory's regional office and ask the factory representative to mediate.

For more money-saving car tips, click on any of the links below:

• How to Choose a Good Mechanic
• Avoid Paying for Extra Options
• Having Your New Car Repaired