I haven't seen their rack in person but I think it sits on top of the stock rack and is stamped sheet steel or alum. When I made mine it was only intended for my own use, I had no intentions of selling them. Consequently, I made it with much more complex machining than is needed, and since I made it myself I added features strictly for looks and to challenge my amateur machining skills. My only motivation was to make something I could be proud of, with no thought of how to make it cheaper. The majority of the cost in mine is the extensive machining of the details and the fact is must be machined on both sides. My rack is so rigid you can support both edges and stand on it and it won't flex. I start with 3/8" aluminum plate because I wanted it to be stronger than needed, and that thickness allows use of all the stock mounting hardware. There are several cheaper and thinner racks available that will adequately support a trunk, I just wanted mine to look better and go beyond the minimum requirement.
