Oprah Winfrey made the wildest dreams of General Motors come true yesterday when she devoted the entire first half of her syndicated talk show's highly anticipated 19th-season debut to GM's new Pontiac G6 sedan.

Her audience didn't mind sitting through a half-hour car commercial -- all 276 of them received their very own G6s because, Oprah announced, this would be her show's Wildest Dreams Come True season. Pontiac donated the cars in exchange for the big fat on-air plug, worth millions of dollars on the syndicated hit series, which last season enjoyed more viewers than in its previous season, and younger ones to boot. National ad rates on "Oprah" are higher than for some prime-time shows, according to trade publication Broadcasting & Cable; last season a 30-second spot on "The Oprah Winfrey Show" averaged about $75,000, Nielsen estimated.

"It's our 19th season!" Oprah roared as she opened the program, high-fiving members of the studio audience, who had been carefully screened to make sure that each was:

a) in need of a car and preferably with some heart-tugging tale;

b) reasonably good looking and well-dressed, and preferably young;

c) lacking the gene that causes one to become embarrassed when seen bawling, screaming hysterically and hugging automobiles on national TV.

"I'm so excited about today's season premiere my heart is palpitating!" Oprah shouted as she touched her hand to the heart area of her trim red Jackie O. suit, shaking her beautiful wearing-them-longer- this-season tresses.

"I'm going to try not to faint, but just in case I do, we have real emergency medical people standing by!" Oprah enthused, as the camera cut to two beefy paramedic types nearby. The audience woo-hooed enthusiastically and clapped.

"Because this is so exciting, you may have heard, sometime during the next 60 minutes we're going to do something big, really big. That's why we have emergency -- you're certified, you've got your little heart things," Oprah said, changing the subject abruptly and turning to Paramedic Men.

"Come, test my heart -- right now!"

"Oooohhh!" audience yelled, clapping, as one Paramedic Man put his "little heart thing" to her chest, gave her a thumbs up and told her, "It's perfect."

Of course it is, stupid. She's Oprah, the Good Witch of the North.

But Oprah is also something of a tease, so at first she called onstage just 11 of the most photogenic/pathetically storied members of her audience to award them their cars.

"But I have one car left . . . and someone in this audience still has a chance to go home with a new, fully loaded G6. G6! G6!" Oprah bellowed, accounting for three of the 15 times she mentioned the car by name during the Product Placement to End All Product Placements.

Then an army of pretty young women circulated through the audience distributing little boxes to the crowd.

"Everybody is being given a special package. I don't want you to open it. Do not open it until I tell you!" barked Oprah, who is also something of a drill sergeant.

"DO NOT OPEN, DO NOT OPEN, DO NOT OPEN, DO NOT SHAKE IT, DO NOT OPEN UNTIL I TELL YOU!" she shrieked, sending her audience into near hysterics.

Oprah explained that the key to the remaining car was in one of the boxes. She then called for a drum roll, because Oprah is also something of a drama queen, and told them to open the boxes.

"YOU WIN A CAR!

"YOU WIN A CAR!

"YOU WIN A CAR!" Oprah bellowed, pointing one by one at different people in the studio.

"EVERYBODY GETS THE CAR!

"EVERYBODY GETS THE CAR!

"EVERYBODY GETS THE CAR!" she screamed. By now she's leaping up and down onstage, audience members are weeping and screaming and grabbing each other.

"And guess what? Hold on, your cars are waiting right outside! How cool is this? Follow me, follow me. I think I'm going to pass out!"

The audience, still screaming and hugging, seemed to understand that she wanted them to follow her outside, rather than follow her as she passed out, and she took them to the parking lot of her Harpo Studios, with her arm draped over the shoulder of one, the same way she liked to be photographed with fellow jury members when she would emerge from a hard day being the center of media attention during the murder trial of Dion Coleman.

"Thank you, Oprah -- I love you!" one woman screamed at the camera; another stepped up on to the frame of a driver's side door and hugged the car, shouting, "Oh, my God!"

Other big companies' wildest dreams came true during the second half of the show, but on a much smaller and quieter scale.

The UPN network -- which is owned by Viacom, which distributes Oprah's show -- also received millions of dollars' worth of publicity when Oprah staged a makeover of a 20-year-old homeless woman by model Tyra Banks, the creator and star of UPN's hit reality series "America's Next Top Model," and Banks's "Top Model" team.

Ditto Jane magazine, which, Oprah announced on the show, has agreed to run photos of the lucky woman.

And telecom company SBC Communications got a nice plug when it awarded the same woman a college scholarship.

After that, Crate & Barrel and Best Buy got on-air mentions and their trucks were seen delivering appliances and furniture to a family with eight foster children in Upstate New York. And Oprah cut a gigantic Publishers Clearinghouse-size check for $100,000 so the family could buy the house from which they were about to be evicted.

She threw in another check for $30,000 to fix up the house "because Oprah thinks of everything," the person who handed the check to the family assured them.

Driving them delirious: Winfrey and some of the 276 audience members who yesterday received new Pontiac G6s, courtesy of show sponsor GM.