Just the other day I was behind a full size van & they had a cargo rack that went into the trailer hitch receiver. The type you can get at Harbor Freight, etc. He had made tall sides for it. Looked like they were made from electrical conduit. There were 2 kayaks standing vertical in the basket. At least 10'ers. Seemed like a slick set-up. The rack sits low, even with the receiver. The top of the kayaks were a few feet above the roof line of the van. I'm sure there were tie-downs, etc. I was too busy checking out the basket.