So I have a knocking in the rear of the car. I knew this was this was the exhaust back box hitting on something. I presumed it was rubber mountings failing. Bought those and put it on the list to do. So while doing the rear brakes and having the arse of the car in the air with the passenger rear wheel off I had a proper look. What I've found has me stumped. Basically the exhaust is hitting off the arb as per the pic. As nothing to push up and downward is the only direction things can go I assumed the worst and checked to see if the rear subframe was backing off. I checked this and while you can see the top of the bushes where it meets the bottom of the car this also appears to be normal as I used an anologue ie another e36 to check this against. Had to double check as I've never paid much attention when taking rear ends out. There was no knocking before I changed the exhaust manifold. This was changed as there was only one stud holding the exhaust to it. I replaced it and made sure the exhaust was refitted correctly. There are no broken drop links or mountings. Everything thing else is as it should be. The only thing I can think of are the after market springs in the rear of the car that the previous owner has installed might be two big and are pushing down excessively. As I had more hassle than normal getting the spring out on the drivers side when replacing the trailing arm, drive etc on that side. That or maybe very worn bushes on the upper wishbone allowing it to sag? Though after having a few of these cars I've never seen that before. In any event I will be putting in new springs, shocks and links during the week with any luck and I'm hoping this will tell me something. If anyone can shed some light on what I may be missing it would be greatly appreciated