Cargo boxes can be used on top of the cargo carries to hold all of your items. The main purpose is to keep things clean (inside the box), not damage your current set of luggage or upset the misses, and sometimes people like to lock up their items and this is a great way to do this.
Not all boxes are weatherproof, not all can be locked, so take a look and let me know if you have more to add.
http://www.cabelas.com/cabelas/en/co...er&noImage =0
http://www.montanajacks.com/index.as...ROD&ProdID=365
http://www.custom-cover.com/details....b1b5247c68513f
http://www.coverbonanza.com/7517/234...argo-Pack.html
http://www.cabelas.com/cabelas/en/te...con&hasJS=true