Do you frequently remove dust from them? Are they exposed to sunlight or humidity?
Here are my two cents, if I may... That presentation is a bit busy and overwhelming. As a viewer, I find myself focusing more on the quantity rather than appreciating the craftsmanship and design qualities of each artwork.
I assume you value them; they represent more than mere functional pieces. If I were in your shoes, I would display fewer pieces but rotate them every two weeks, properly storing the others. I would also keep the ones I frequently use within easy reach on the wall. Having fewer pieces displayed would make it easier to enjoy organizing them by categories/themes (open-wheelers, prototypes, GTs, customs) and keep the collecting experience entertaining. It would also leave room for decoration/scenography (related pictures, stickers, livery colors). Additionally, I would add a small card for each displayed piece (with its history, information on the manufacturers, materials, races won, previous owners, etc.), similar to what museums have next to art pieces.