Abstract: An underseat storage bin is used with a pivotable vehicle bench seat in a vehicle having a floor surface. The bench seat is pivotable between a horizontal seating position and an upright stowed position for providing access beneath the seat. The bench seat is supported on seat support members at opposing ends. The storage bin includes a blow-molded bin structure having first and second ends removably attachable to the seat support members. The bin structure includes a plurality of generally vertical compartment walls arranged to form a plurality of storage compartments. At least one of the storage compartments extends substantially the entire length of the bench seat for storing long items. The compartment walls form open bottoms therebetween, such that the vehicle floor surface forms the bottom of each storage compartment for supporting items stored in the storage bin.