Over 5 of the months in the RV are in FL and the other time in TX usually. Still look like new as I said; no cracks, still very flexible, new and shiny
. I will say that all my tires have slides that extend out over them so the amount of sun they see directly is very small.
Note: DW just said if you had a sewing machine you could buy some material (burlap, canvas?), cut a pattern then make your own covers....