MEXICO CITY (October 13, 2012)--Mexican customs agents seized $560,000 in cash hidden in the door panels of a vehicle that entered Mexico at Matamoros, across the border from Brownsville.

The Tax Administration Service said in a statement Friday that the driver drove into the "nothing to declare" lane, but when the driver hit the button that doles out random searches, he got a "red light,” meaning he had to be searched.

Agents then found 35 packages of cash hidden inside the rear door panels.

The Tax Administration Service oversees customs agents, who have seized more than $50 million at border crossings since late 2006.

Drug cartels frequently smuggle the cash proceeds of U.S. drug sales back into Mexico, often to pay suppliers.