I gutted my 325i to remove all the sound deadening tar. It wasnt that naked but pretty close. Puttin it back together is the hard part.
I havent seen rust on my last 2 e30s(need to check my 318) in the spots you've mentioned. I'd imagine it would be a common area though.
Just for the record. Its really not much louder in the car with all the deadening removed.
Is that car on its way out? last horahh before the scrape heap.
Hunter