A storage unit capable of being mounted on a shelf on the rear of a vehicle is designed to protrude from the rear of the vehicle to provide more storage space. The storage unit is further designed to be removable, and may be subdivided with movable partitions. The storage unit may be further designed to provide a controlled temperature environment inside. It may be further designed specifically for use on the rear of a golf cart type vehicle, which may include adjustable feet to help hold the storage unit on the rear of the golf cart type vehicle. The storage unit may also be designed to allow for foldability, such that it can be more compactly folded and shipped, stored or transported. There may also be a storage box provided to store the folded storage unit above a vehicle such as a golf cart.