Abstract: An under-seat storage device made of an expandable material which in a first embodiment comprises an accordian-shaped configuration. Other embodiments include Spandex rope or other mesh type fabrics having other expandable qualities. The material has a top portion having a plurality of VELCRO.RTM. strips clips, magnet(s), screws, bolts, adhesive, wing-nuts, etc. attached thereon, three side portions having accordion folded or other expandable surfaces and a front portion having an articulable flap which opens towards a bottom portion, and a VELCRO.RTM. (or other fastening material) strip in the center thereof. A plurality of VELCRO.RTM. strips are also located on the bottom of a folding seat such that the storage unit may be readily attached and/or detached from the bottom of the seat by pushing the VELCRO.RTM. strips together or pulling them apart. The storage unit may also include a smaller center container attached to the storage envelope.