Huh?
Do you mean like the nests the little bastards used to build all the time in my 535's cabin air intake ducting. Those nests? The ones that clogged up the blower and evaporator? Them? Not to mention the fun and games when one of them would bring something in that died? Eh?
I'm sooooooo happy with the cabin air intake and filtration in my E39!
Edit: Ok, it makes more sense now that you included the picture. Critter nests happen all the time.