yeah I've been looking into that as well, as you tend to get a subtle rainbow halo around light especially if its raining. I will definitely look to add that in my next update.
Thats the moon though but you get what I mean.
Been thinking of trash props as well. I'm going to do some cigarette butts as decals with some bits of paper mixed in, newspaper, some plastic carrier bags, some soggy cardboard boxes, bin bags, some cans/bottles. maybe some more nasty type things like puke or a used condom not too sure on that though ^^
Only thing with the fog is it maybe a touch to dense?