A utility cargo carrier attachment fits to the rear of an existing vehicle such as a van. The carrier extends across the entire vehicle width from the rear bumper up to the vehicle roof line. A unique mounting arrangement uses existing rear access doors and existing tow bar structure to rigidly but detachably mount the carrier to the van. The carrier is completely enclosed for cargo protection and is accessible with hinged doors. The interior of the carrier is equipped with shelves to improve space utilization. The entire structure is out of the air stream of the vehicle thus providing excellent fuel efficiency. The weight of the cargo is supported by existing tow bar structure and lateral rigidity is provided by serpentine tee members inserted into existing hinged door cracks. The tees are frictionally engaged in the cracks by the tightening of a securement bolt against a protective resilient pad facing the van exterior. The tees are adjustable on a carrier cross bar to provide for attachment to different sized van doors.