A team of state inspectors strode into the Blue Wave Car Wash in West Los Angeles, past latte-sipping customers in electric massage chairs and into the gritty carwash tunnel.

"¿Cuánto gana usted?" the inspectors asked worker after worker, about 20 of them, most Latino immigrants. How much do you make? Each carwashero responded that he earned minimum wage or more -- just as the owner of the Blue Wave, one of the region's busiest carwashes, had told the inspectors.

Looking over payroll records, however, the regulators became suspicious. Employees who said they were full time were listed as working just 10 or 15 hours a week.

Inspector Martha Mendoza ushered Juan Cruz Santiago, a small man with salt-and-pepper hair, away from the others. During gentle questioning under a ficus tree, he admitted that most days, he and his 66-year-old father worked for tips only. So did nearly half the other employees, he said. It had been that way for at least six years.

"It's bad," the 41-year-old Oaxacan immigrant whispered to Mendoza, his eyes darting nervously toward his boss' office. "Other carwashes are the same, no?"

Many are. A Times investigation has found that hand carwashes, automotive beauty shops patronized by tens of thousands of Southern California motorists every day, often brazenly violate basic labor and immigration laws, with little risk of penalty.

Half or more of carwash owners flout the minimum-wage law, estimated David Dorame, the longtime lead investigator for low-wage industries at California's Division of Labor Standards Enforcement.

Despite many undocumented workers' reluctance to complain to authorities, employees at a fifth of Southern California's carwashes in the last five years have formally accused owners of illegally underpaying them, The Times found.

From Santa Monica to Westwood to Koreatown, many workers said they received only tips for some or all of their shifts. Labor division inspectors estimated that about 10% to 20% of car dryers are not paid by owners.

"Tips only" is a requirement for some new workers until owners are satisfied that they can properly dry a car, laborers said. Their take is typically $10 to $30 a day.

At the Blue Wave, owner Isaac Shanfeld of Beverly Hills told inspectors that all of his workers earn at least minimum wage, costing him $700,000 a year. He said he didn't know of anyone working for tips alone, but added: "I can't police everyone." After the inspection last fall, he was issued a $2,600 citation for wage violations.

'Want to go home?'

Paid workers at some of the other 1,000 washes throughout Southern California said they earned as little as $1.63 an hour. As of January, the minimum wage was $8 an hour.

"We sweat like animals," said detailer Manuel Varela, 42, who until recently worked at a carwash just west of downtown Los Angeles.

To survive, carwasheros often pool resources, cramming into cheap one-room apartments, sometimes sleeping side-by-side on the floor like, as one worker put it, salchichas embolsadas, or stuffed sausages.

"Employers feel out the lowest amount these workers will take," said Timothy Kolesnikow, a former attorney at California's labor division who now represents carwasheros and others in his private practice."People don't realize the human misery involved in getting their cars washed. There is a dark side to this."

Desperate for a toehold in the region's underground economy, many in the largely undocumented workforce are loath to complain for fear of being fired, physically threatened or deported.

Pedro Guzman, an undocumented Honduran immigrant, said a manager at a Hollywood carwash was able to keep employees washing at a furious pace -- 350 to 700 cars a day -- with two words in ungrammatical Spanish: "Quiere casa?" "Want to go home?"

Immigration authorities have done little to discourage the steady flow of undocumented workers into carwash jobs, affording owners an endless supply of cheap, eager and easily exploited laborers.

Despite the national debate over illegal immigration and a recent crackdown on some employers, U.S. Immigration and Customs Enforcement officials say they have not raided a single California carwash in at least four years.