SACRAMENTO, Calif. -- Sacramento sheriff's deputies cracked open their biggest cocaine case ever, and they say that area residents may have run into the traffickers if they recently had work done on their car.

Deputies descended upon Southside Transmission on Franklin Boulevard Thursday. About the same time, police in San Antonio stopped a car that was on its way from Mexico to Sacramento. They said that they found 49 kilograms of cocaine in the vehicle. That's more than 100 pounds. It's worth about $10 million on the street.

"They found a hidden compartment that was welded into the back section of the car, in the back seat into the trunk. That contained the 49 kilos," Sacramento County Sheriff's Sgt. James Lewis said.

So far, 20 people have been arrested, including Antonio Villasenor, who, investigators say, was the kingpin of the operation. Investigators say that he was using family and friends to move the drugs in and out of the transmission shop.

"It's an ability to launder money. It's an ability to have people come and go without notice. It's an ability to bring a car in and do some kind of modification to transport something," said Office of Criminal Justice Planning spokesman Allen Sawyer.

"Deputies said that every now and again the transmission shop would do a few real jobs, just to keep up the appearance of a legitimate business. But neighbors say that they knew for a while that it was all just a front.

"New cars would come in every day about 3 p.m.," said radiator shop worker Bob Sturges.

Investigators said that the network had been operating for about two years and that there's no way to tell how much cocaine made it through in that time.