Thanks for the comments!
I took way too long to post photos. I found my m3 in mid July after almost 6 months of searching for the right one.
The exhaust was fitted by BMW by the previous owner. I am the second owner. It is a BMW performance exhaust. I think it gives a slightly better sound, not sure about power gains. I shall have to have a dyno test performed to confirm.
The v8 sounds awesome - I have always had a thing for the sound of a v8.