flores-montano ("flores") was driving a 1987 ford taurus station wagon as he attempted to enter the united states through the port of entry at otay mesa, california. a customs inspector referred the vehicle to secondary inspection, where a second inspector tapped the gas tank and noticed it sounded solid. the second inspector summoned a mechanic who, less than half an hour later, arrived and removed the gas tank from the car. the mechanic then removed an access plate from the tank and found 37 kilograms of marijuana. the process of removing the gas tank took between 15 and 25 minutes.