SAN DIEGO -- When Adrian Rodriguez heard a rattling noise in the 1991 Volkswagen Passat he'd bought at a U.S. Customs auction, he hoped to fix it cheap by taking it to his mechanic in Tijuana, Mexico. But the problem came with some unexpected costs.

Under the back seat, the mechanic found a hidden compartment, where Rodriguez says he was shocked to find 33 pounds of marijuana. He immediately called police, who in turn, put him in jail.

The experience has put the slender, soft-spoken social worker in the middle of a campaign to overhaul how U.S. authorities inspect vehicles seized at border crossings and in drug busts.

Some critics question whether the government should be in the used-car business at all, despite the millions of dollars raised in the sales each year. About half of the 11,000 vehicles auctioned annually are sold in San Diego and many of the rest are sold in other cities along the border.

Rodriguez's case is the latest of several involving cars sold with drugs inside.

'Something righteous'

"The law has always worked to protect me and my family," he said. "In my mind, I was doing something righteous, correct, and I still feel that way."

Rodriguez, 25, was held for a month in the La Mesa State Penitentiary on drug possession charges before a Mexican court freed him on Aug. 14.

False imprisonment isn't the only risk in these auctions. Timothy Stutler, an assistant U.S. attorney in San Diego, fears smugglers may buy auctioned vehicles to ply their trade -- if they get caught, they can say the drugs were there before.

Daniel Clar, general manager in San Diego for Robertson Leasing Corp., which runs auctions for the U.S. Marshals Service, says his crews have found drugs at least four times in recent years.

Ecology Auto Parts in Santa Fe Springs, which has bought thousands of vehicles at government auctions, has found drugs in about five, said retail manager Joe Kellejian.

"We've seen it in engine compartments, fake gas tanks, side panels in trucks, inside spare tires," Kellejian said. "We immediately call the authorities and ask them to remove the vehicles from our premises."

Customs auctions

Customs, which auctions about 5,000 vehicles a year, suspended sales nationwide in August. It promised new inspections, requiring that dogs search every vehicle when seized and again when put up for sale, and submitting nearly all to X-rays.

The Marshals Service, which auctions about 6,000 vehicles a year on behalf of the FBI, Drug Enforcement Administration and other agencies, leaves inspections to whichever agency seizes the car, said spokeswoman Mavis Dezulovich.

The Treasury Department, which formerly oversaw Customs, and the Marshals Service are named in separate lawsuits by Mexicans who say they were jailed after unwittingly buying drug-laden cars.

Jose Aguado Cervantes claims he didn't know about the 119 pounds of marijuana stashed in a Buick Century wagon he bought at an auction in July 1999 until he was stopped at the Otay Mesa border three months later. The 68-year-old retiree spent three months in a San Diego jail.

A federal appeals court said in June that Cervantes could pursue a negligence claim, rejecting the government's argument that Customs is exempt from liability. The court said the government's position was "so off-the-mark as to be embarrassing."

Last year, Francisco Javier Rivera and Alfonso Calderon were stopped by Mexican soldiers who found 30 pounds of marijuana under the upholstery of their Nissan Pathfinder. According to a lawsuit filed in federal court, Rivera bought the Pathfinder in September 2001 from Customs, seven months after it was seized with 59 pounds of marijuana.

The men spent nearly a year in prison before a Mexican appeals court overturned their convictions.

Rodriguez also plans to sue Customs, calling his Tijuana jail time "a month of terror."

A native of San Bernardino, Calif., Rodriguez lived his first 11 years in Tijuana with eight relatives in a one-room home made of wood scraps. As a teenager, he lived with his grandmother in Chula Vista, where he was involved in his church and school, including the chess club and wrestling team.

"He was always as straight as an arrow," said Ruben Ledesma, former coach of Montgomery High School's cross-country team. Rodriguez was captain for three years.

Rodriguez graduated from high school with honors and earned his bachelor's degree in human development from the University of California, San Diego in 2001.

He now earns $10.75 an hour counseling troubled children, and supports his 24-year-old wife and their 14-month-old son.

While in college, Rodriguez bought a Jeep Cherokee at a government auction. A satisfied customer, he later spent $200 for a Volvo, $70 for another Volvo, $400 for an Audi, and $600 for the Passat.

The Mexican government impounded the Passat. Rodriguez said the Audi's transmission died, and he sold one of the Volvos to a scrap yard for $40.

He says he will sell the remaining Volvo for scraps.

"It works fine, but we don't want to touch it," he said. "How can you be secure?"