SportRack Skyline XL Roof-Mount Cargo Box for $99.00. Select in-store pickup at Walmart to save on shipping surcharge. Otherwise, shipping surcharge is $39.99 for a total of $138.97 shipped. Here is a screenshot for your reference. It is made from UV-resistant, high-density polyethylene, has 18CF storage space, fits on most factory crossbars, as well as other round and square bars with a 4″ diameter.