Abstract: A briefcase adaptor includes a planar top surface supporting nested inner and outer trays. The inner tray is removable and includes hook and loop type pile fasteners for releasable engagement with cooperating fasteners secured to the top surface of a conventional briefcase. A raised spaced floor of the adaptor includes two compartments for holding miscellaneous items such as a clipboard, books, documents, etc. A beverage holding console extends along one side edge of the adaptor and includes a top surface provided with a plurality of apertures for storage of beverage containers and miscellaneous items such as a cordless phone. Beverage receptacle apertures include slotted portions for positioning a handle on a mug type beverage container. A pyramidal positioning block extending along an opposite lateral side of the adaptor is dimensioned to be received in a central recessed portion of an automobile seat back portion adjacent a junction with the automobile seat bottom portion.