With the rear body tipped there is access to a storage area on each side of the chassis. In addition, although it's not specifically designed with this in mind, there is a central area between the main chassis members which could also be used for storage, e.g. of ropes or cables.
A word of warning, it is very easy to reach out and pick up the truck by taking hold of either side of the cab roof - don't, it comes off easily!