02/1985 535i 3.5L
I'm trying to replace my exhaust system and I need to know what parts I
need from the manifold all the way back to the and including the muffler.

It's all rusted. Every part of it.

I would also appreciate any input on where I could buy all the parts and a Bentley manual.

Yeah, it's time to fix some things. It's really been an awesome car.
When I bought it, it had been sitting in a garage for several years and would not go foward very well or run for very long. I paid $1000 for it and tried to get it working the best I could, engine analysis is not my strong suit, so I took it to some BMW mechanics and they did a bunch of repairs and got it running real nice. But now it is time for drive shaft, brakes & rotors all the way around and a complete exhaust system. I haven't been under it since last year and I am waiting another week for the weather to break. Then when the parts come in I'm all over it. I can't wait. I've been taking it real easy on first gear because of the loud clunk. This summer my car is gonna rock.

Anyway any info is very much appreciated.

I found the Bentley manual through Amazon.

I've ordered the drive shaft and related parts.
I've ordered brakes and rotors.

I found bimmerzone for parts on here. This site is pretty big.
Larger and more one-stop info than i'm used to.
My head is going to explode. ; )