
The ratchet straps have flat metal hooks that use the lip on the underside of the top of the body side panel.

I added an aluminum bar using some spacers and the mounting holes for the seat to anchor the other end of the ratchet straps.
I took the Pinzi out for the first time with this setup over Memorial Day weekend. I was with a group that went to Coyote Flats and Sanger Meadows in the Sierra Nevada mountains outside of Bishop, CA. The boxes were rock solid. I was able to negotiate the very rough trail to Sanger Meadows without any problems. So far, I'm very happy with this setup. I can carry my gear and still leave a narrow aisle in the middle.
Another addition is a real mattress for my bad back. A half queen mattress fits perfectly on the folded seats. It always seems luxurious to sleep between sheets while camping. You can even get fitted sheets for a split queen mattress on the Internet.