The convertible Mercedes Benz, filled with bags of unused concrete, was discovered Thursday by landscapers in the affluent town of Atherton in Silicon Valley, Atherton Mayor Rick DeGolia said, reading a statement from police.Although cadaver dogs alerted to possible human remains on Thursday, none had been found more than 24 hours after technicians with the San Mateo County Crime Lab began excavating the car, DeGolia said.Police believe the car was buried 4 to 5 feet deep in the backyard of the home sometime in the 1990s — before the current owners bought the home.Cadaver dogs were again brought back to the house and again “made a slight notification of possible human remains,” DeGolia said.In the late 1990s, Lew was arrested for insurance fraud after he hired undercover police officers to take a $1.2 million yacht “out west of the Golden Gate Bridge into international waters and put it on the bottom,” The Chronicle reported."