McDonald's Corp. and General Motors Corp. wanted to plant upbeat references to their products in the script of Spain's top-rated television show, "Aqui no hay Quien Viva" ("No One Can Live Here"). In Spain, the world capital of TV ads and plugs, the writers were more than happy to oblige.

The result: Zany characters named Emilio and Belen stage a wedding as a ruse to get gifts from their friends. Instead of having a fancy reception, Emilio has a surprise for his guests -- dinner in a Hummer served from a McDonald's drive-through window.

Spain has more product placement and more commercial breaks than just about anywhere else. In prime-time evening hours, commercial breaks can last 15 minutes and contain up to 30 ads in a row, so long that some viewers forget what they're watching.

Home-improvement show "Decogarden" had the most product placements in a Spanish show: 105 in the four, 45-minute episodes aired in just one month. The show's creator, celebrity chef Karlos Arguinano, produces two other shows, packed with brand-name kitchen appliances and power tools.

The sitcom "Los Serrano" ("The Serrano Family") once took a scene directly from a Coke ad, featuring a daughter telling her mother she's going to the library. Instead, she actually sneaks off to see her boyfriend, carrying a Coke. A few weeks after the ad ran, the sitcom featured the same scene, only this time with the show's characters, in return for a payment by Coke.

Spain has permitted rampant product plugs despite a European Union ban on product placement and a limit on commercials. The rules aren't enforced in Spain because the EU can't directly enforce policy. Spain, unlike Germany and the United Kingdom, also doesn't have its own rules governing the separation of content and advertising.

The rest of Europe is moving toward the Spanish model. New EU rules set to become law in the summer will let broadcasters decide when to schedule commercials and product placement.

The new rules have "paved the way for making Europe's audiovisual sector more competitive with the U.S.," says Martin Selmayr, a European Commission spokesman.

Spanish producers aren't complaining that the commercialism intrudes on art. Instead, they say it helps preserve local TV production at a time when many channels across Europe are airing U.S. shows at less expense.

Antonio Saura, director general of Zebra Producciones SA, a film and TV studio in Madrid, envies the big budgets of U.S. shows like "Grey's Anatomy" and says he'll happily change a script for an advertiser if that doesn't substantially alter a story line.

"We are a paradise for product placement," says Javier Hoyos, head of ad agency Havas SA's B6 Spain marketing unit, who has brokered product-placement deals with "Aqui no hay Quien Viva." Mr. Hoyos says he recently signed a deal with a spinoff of the show for a France Telecom SA mobile-phone store to appear in a building where the characters live.

At Omnicom Group Inc.'s OMD Fuse agency, which negotiates to place products in TV shows on behalf of advertisers, manager Jose Dosal typically receives scripts from a studio before episodes are filmed. The agency came up with the idea of including McDonald's in "Aqui no hay Quien Viva," Mr. Dosal says, after it looked over several scripts from the show's producers and spotted the wedding-party scene.

In the show, as the bride and groom pull up to the window, they shout out McDonald's menu items by name. "That's 37 Big Macs, 37 fries, 44 McNuggets and 30 salads with chicken. Would you like any dessert?" asks the McDonald's sales clerk.

"Los Serrano" signed a deal with Nissan Motor Co. for the show's family to drive a Pathfinder SUV. Under the contract, the Pathfinder in the show can never be stolen, break down or be driven in heavy traffic. The car can't be filmed from the rear.

"We don't want the camera to make it look plain," says Nissan Spain's advertising manager, Belen Garcia.

Ms. Garcia receives "Los Serrano" scripts two days before filming so she can make changes. Recently, she says she inserted dialogue to make a clearer reference to the car's GPS navigation system. A spokeswoman for the "Los Serrano" producer Globomedia SA says the use of real-life products in its shows provides an "accurate image of current society."

The show also has a deal with Sogecable SA, Spain's satellite broadcaster. When teenage character Marcos broke up with his girlfriend, the show wrote in a plug for the satellite service, to position it as the best way to cheer up the brokenhearted teen. His uncle Santiago, played by Jesus Bonilla, said: "We'll sign up for the satellite and it will take two days to set up."

Marcos later informed his brother Curro that the service has something for the whole family. "Now you can watch all the cartoons you want, and dad can watch the soccer," he said.

Spaniards continue to watch a lot of television. According to Barlovento Comunicacion, they average three hours and 35 minutes a day.

But the ad blitz has some viewers in despair. Andres Camacho, a 30-year-old financial analyst in Madrid, recently considered watching "Lord of the Rings" on TV. But when he checked the TV listings, he saw that the running time for the three-hour film, with ads, was five hours. "When I saw that, I thought, 'There is no way I am going to enjoy this movie,'" he says.

Often it can be hard to tell the difference between ad and show. On TV one evening, two main characters on crime drama "The Police Commissioner" were trying to send a crime report to headquarters. "I have to send this report and there's no Internet connection, no WiFi, nothing," one policeman said. "Don't worry," replied his colleague. "I've got a Vodafone portable Internet device." She pulled the device out of her pocket and showed him how to use it.

While the scene fit the plot of the show and featured the same actors, it wasn't actually part of it. It was a Vodafone Group PLC ad that ran during a commercial break. For viewers, the only tip-off was the word "telepromotion" in small type at the top of the screen.

Vodafone's Spanish online store sold out of the mobile Internet devices two days after the episode aired, says a Vodafone sales representative in Madrid. Vodafone says it usually buys one telepromotion in each "El Comisario" episode.