Here is my bottom competition cart bottom shelf invention until I think of something more permanent. It is just a piece of 32 x 22 x 1/2” plywood painted by the Mrs. I had the shelf ready to install when I received the cart. I used the cart size outside dimensions 33.25 x 23" that are in the RT-590 accessories website and guessed cutting the plywood slightly smaller to 32 x 22”. It is not attached, just lying on the cart’s end frames. Inserted the plywood when I put the cart together. I am just going to use the shelf to store small things like the grate brush, gloves, smoke tube, grate lifter tool, grease bucket liners, etc. I think a nice more permanent shelf would be a stainless steel grate.