Okay, I've already suggested this item but that was before I knew the shopping cart was a vehicle. Perhaps we could include a travois (a stick frame with a fabric or hide sling that is pulled behind a person (or often a dog) in order to help carry extra supplies). It could (rarely) be found, but could be crafted. The crafting recipe might be something like: 8 branchs + 12 bits of string + 8 plastic bags + multitool = Travois + multitool or: 8 branches + 12 bits of string + 20 squirrel pelts + multitool = travois + multitool. It should be a little smaller capacity than a shopping cart (IMO), but big enough to lay, say, two backpacks out on.