I know this sounds a little petty compared to a lot of other suggestions, but personally I'd think it was cool if when inside you could maybe hear the rain on the windows? I think it would be a nice addition because it's just a calm, relaxing noise (to me at least) and seeing as though I generally sit inside it would give sitting inside my safehouse a cosy atmosphere. Like I said, maybe not something everyone else would like to see as much as me and not a high priority, but I figured I'd post it anyway.