(MONEY Magazine) – You have your heart set on that one car. You love its svelte styling, pulse-pounding acceleration, great handling and...extra-long warranty? Well, maybe not the warranty. Still, some manufacturers are trying to entice buyers with better guarantees. In particular, Korean car maker Hyundai recently announced the longest warranty in the business on its 1999 models.

Hyundai will pay for repairs for up to 10 years or 100,000 miles (whichever comes first) on your car's so-called power train, which includes the engine, transmission, axles and other parts that actually drive the car--and also generate the biggest repair bills when they fail. Hyundai's bumper-to-bumper coverage, which includes virtually every system, lasts for five years or 60,000 miles. In contrast, most cars, sport utilities and vans carry only a three-year/36,000-mile warranty for everything. Plus, Hyundai throws in free roadside assistance for five years.

Hyundai isn't the only car maker with a notable warranty (see the table at right for the four longest). The warranties on most luxury cars last at least four years or 50,000 miles. Volkswagen and Audi pay for routine maintenance during the bumper-to-bumper warranty period (a below-average two years for VW, three for Audi). bmw has similar maintenance coverage for the first three years of its four-year warranty.

So what's behind this generosity? First, warranties are a cheap add-on. "Almost all cars are reliable now," notes George Peterson, president of the research firm Autopacific. "Extending warranties does not cost manufacturers as much as in the past." Second, automakers can use a warranty to offset consumer doubts about reliability. In the early 1990s, Hyundai was plagued by engine, brake and electrical problems on its now discontinued Excel. Volkswagen, the only other brand with a 10-year or 100,000-mile power train warranty, launched that coverage when sales were poor in 1993. Finally, luxury-car buyers who spend upwards of $40,000 on a car expect nothing less than a topnotch warranty.

If you've narrowed your choices to two similarly priced cars--say a Hyundai Elantra and a Dodge Neon with a 36,000-year/three-year warranty--the longer warranty can be valuable enough to break the tie. One new transmission alone can cost as much as $2,000.

The appeal of a warranty is greater than it used to be now that dealers are less likely to give you a hard time about doing repairs under warranty, says Clarence Ditlow, head of the consumer group Center for Auto Safety. "In the past, dealers got paid less for warranty work than for work charged to customers," he notes. Now manufacturers pay retail rates.

Just make sure you'll keep the car long enough to benefit from the warranty. If you buy a new car every four years, 10-year coverage will be of little use. But if you lease a car for only three years, a warranty that covers all maintenance, such as Audi's, BMW's or Volkswagen's, can pay off. Routine maintenance can total $500 to $1,000 over three years.

Once you own your car, make sure you don't jeopardize your coverage. If you have an independent shop install a car alarm or a Lo-Jack theft-tracking device, for example, you could lose warranty coverage for the electrical system in your car. Stick with the dealer, even if you have to pay more. Plus, if you don't use the dealer for servicing--which most car makers allow--keep records.

Finally, don't assume longer is always better. Most dealers will try to sell you an extended warranty. In most cases, just say no, especially if you expect to keep your car for less than five years. According to the magazine Checkbook, which runs the car-buying service Car Bargains, the average buyer pays $1,000 for an extended warranty but collects only $250 under its coverage. Instead, start a savings account for future repairs.