Oprah Winfrey kicked off more than a TV season when she gave away 276 new Pontiac G6 sedans on her show last week. Her headline-grabbing stunt also launched the domestic auto industry on a crusade to reclaim credibility in the American passenger car market.

This fall, the Big Three Detroit automakers are making a high-stakes push to win back car sales from overseas rivals such as Toyota Motor Corp. and Honda Motor Co., which in the past decade have dominated a segment that was once a staple of the domestic industry.

U.S. automakers have neglected the passenger car for years to instead feed the public's appetite for trucks and sport-utility vehicles. The three top-selling cars in the United States are Japanese brands, according to Ward's AutoInfoBank, only a decade after the Ford Taurus reigned as the standard-issue sedan for Americans. Domestic car brands consistently rate lower than the Japanese in consumer quality surveys, and U.S. manufacturers rely on heavy discounts to boost their total sales figures.

Many experts doubt Detroit can quickly turn around a decade of decline and woo skeptical Americans back to domestic sedans. But manufacturers are hoping they can at least stop the slide by flooding the market with new products.

"People aren't ready to give them the chance again," said Wes Brown of Iceology, an auto industry marketing consultant. "But the argument could probably be made that . . . at least if they can get some strong product out there, then three or four or five years from now, consumers might feel a little more confident in looking at the Big Three on the car side."

New products are starting to roll out at a mind-boggling pace as Ford, General Motors Corp., and the Chrysler Group of DaimlerChrysler AG remake their entire lineups of passenger cars. "It's reached the point where the cars they have in many cases are so old that they're not even given consideration anymore by consumers," said Art Spinella of CNW Marketing Research Inc. "So they have to do something."

Get ready for big new advertising campaigns and more product tie-ins with entertainment programs. Pontiac will be all over this season's installment of "Survivor," for instance, and the company is backing a syndicated TV show about the secrets of Hollywood stunt drivers -- all of whom happen to use Pontiac products.

Ford plans to spend a record amount on advertising in the final three months of the year, mainly to boost awareness of two brand-new nameplates, the Five Hundred sedan and the Freestyle crossover/wagon, spokesman Jon Harmon said. With a redesigned Mustang, a new Mercury sedan, a jazzed-up Super Duty pickup and the Escape Hybrid SUV also rolling out, "this is the most new product we've ever had at once in our history," Harmon said.

Ford will debut a new slogan in mid-October, replacing the recent "Look Again" with an as-yet-undisclosed tag line that's more "proud and confident," he said. And look for Ford vehicles in such TV shows as "Alias," "24" and, in a new deal, Fox's popular teen drama "The O.C."

"We've been almost off the radar screen of passenger car buyers," said George Pipas, Ford's in-house sales analyst. "Our aim is to get back into consideration."

Dealers, who have suffered through a massive slump in domestic-brand car sales, are ramping up in anticipation. Field Buick/Pontiac/GMC in Arlington has seen its sales staff dwindle to 12 from about 20 in the past year, said Doug Burum, the sales manager. With the new G6 -- a four-door sedan that replaces the Grand Am -- due in about two weeks, the dealership plans to hire another 10 people, he said.

"I think Pontiac has got an opportunity to turn the whole thing around where we can get some of that market share back from Toyota," Burum said.

That's a tall order. Solid sedans such as the Toyota Camry and the Honda Accord have been the backbone of those companies' drive for more market share, and now they're making strong inroads into trucks, SUVs and minivans, challenging Detroit on every front

The Asian companies have not neglected cars, either, with Toyota introducing a new line of entry-level cars under the Scion nameplate and with Honda not only revising the Accord but, this fall, offering a powerful gas/electric hybrid version.

No domestic manufacturer is more against the wall than Ford, where car sales have cratered -- down 26 percent in August, compared with the same month a year ago. Now primarily a truck company, Ford has proclaimed 2004 the "Year of the Car," and the products to back that up are just starting to hit showrooms.

"Two [customers] are already fighting over it," Cowles Ford salesman Tom Sessions said late last week, pointing to the frosty green Five Hundred that had just rolled into his Woodbridge showroom. He and the rest of the sales staff test-drove the new models a few weeks ago at a Ford training event at RFK Stadium, and "we got all fired up," said Sessions, who has been selling Fords for 15 years. "This is going to appeal to a larger base than your traditional Taurus."

The dealership is counting on it: Cowles is about to move to a new, 100,000-square-foot facility and nearly double its sales staff.

But while the stylish new Mustang is regarded by critics as a sure success, the Five Hundred and the Freestyle are seen as less bankable.

"They're going to have a much tougher time in the market," said Iceology's Brown. "They're conservatively styled, and the market is proving that consumers do want vehicles that are more of a fashion statement."

He cited Chrysler's new 300C sedan and the Dodge Magnum wagon as examples -- striking-looking vehicles that helped boost that company's sales for August when most competitors were suffering. Chrysler got a jump on its rivals by releasing those 2005 models over the summer. More are on the way next year, including the new Dodge Charger, a sedan version of the Magnum.

Ford's less flashy sedans may succeed mainly by preventing the company from declining even further, Brown said. GM, which is rolling out new Buicks and Chevrolets as well as Pontiacs, may be in the same position, said Paul Taylor, chief economist for the National Automobile Dealers Association. "I think a lot of the new designs are defensive as well as offensive, in the sense that it would be a victory simply to stop the erosion of the car portion of GM's market share," Taylor said.

The U.S. companies have to fight back, experts said, because they can't afford to cede the passenger car to the competition. Today's hyper-competitive environment demands that automakers offer a full line of vehicles to suit every type of consumer. It's also a matter of pride.

"This company has been built on being a full-line manufacturer, strong from top to bottom in all segments," Ford's Harmon said. "A car for every man -- that was Henry Ford's idea way back when."

What's more, the domestic industry, with its unionized workforce and big pension and health care obligations, simply needs to keep factories running to have any hope of making money, analyst Spinella said. "You can't make trucks in every plant," he said, "because then you're literally forgetting about 40 percent of the market" that still prefers cars.

He credited Pontiac with scoring huge points by debuting the G6 on "The Oprah Winfrey Show" and said the stunt has already caused a spike in brand awareness on consumer surveys. Mark-Hans Richer, director of marketing at Pontiac, said the idea for the giveaway came up nearly a year ago as staffers debated ways to promote the new sedan among women. The carmaker footed the $7 million bill for the promotion.

"We didn't want to do something that could be easily replicated by one of our competitors," Richer said, adding that Pontiac was surprised by the level of publicity that followed the stunt, from mentions on newscasts and talk shows to ranking as the No. 5 "Play of the Day" on ESPN Sportscenter. "Lots is at stake," he said.