I have an empty owners manual folio case. It's black leather, has a BMW snap lock button.
Came from my previous e92 that got totaled and towed and as I was waving good bye, still had the case in my hand. That was the last time I saw that car, but then I got a new one and didn't think about this spare case until I found it when clearing the garage this week. Maybe someone here needs it. Happy to ship at your expense or local pickup in SF Bay Area.