Wish this one was out there before I spent big money on the Yakima roof basket. It is 23 inches wide. So is my Yakima basket, and it just barely fits to the side of my roof vent on a Five Wide. I got the extension, so I have 72 inches long or so. I don't need that much space but it about matches the length of the awning on the other side. The Avenn is probably made by Yakima, it looks so much like it.
Kuatt makes a skinny one also.
I couldn't use a box thing up there or could not go in garage. The basket just barely fits in through the door.
My problem, however, I carry my Clam shelter up there, and if it rains, my screen room gets soaked. I have not found a waterproof cover long enough for the Clam to go in. I asked the Quick-set people, and their only suggestion was to get a large pvc pipe to stuff it in and put ends on it. That would be a slippery and heavy thing to get up that high for on and off while perched on a small ladder..
I might bother Yakima with the problem.
etrailer.com. Really helpful.