I had my Diamond Shield film installed by Diamond Shield in 2006. DS claims on their website that they manufacture their own product. I tend to doubt it. I think it is either Llumar or 3M. Both have had mildew problems and both have claimed they had solved them when I bent over for it. I was aware of the problem when I had it installed. Mine started to fail in warranty, which I was told was five years. Their idea of standing behind their product was offering me free film if I paid $700 to have the old film removed.
My response was to tell them to pound sand and took it off myself. And I tell everyone with an RV about my experience. Often, twice.
Diamond Shield sucks.