The part in the red circle is composed of 3 pieces, P/N 210 492 71 41 (bracket), P/N 210 492 72 41 (bracket), and P/N 202 990 03 10 (bolt). The brackets fit above and below the pipes and the bolt clamps them together. The part in the green circle is actually partially or completely missing. I believe that part is on the driver's side pipe. The P/N is 202 492 02 81 (sealing ring). To replace it you will likely have to separate the front and rear sections of the exhaust system. Separating the front and rear will mean the passenger side seal, which seals a "slip joint", will probably get damaged and need to be replaced. P/N 126 997 00 41 (slip join sealing ring). The bolts for these joints are M8 x 53mm P/N N910 143 008 017 and the nuts are P/N 000 990 32 50 (M8 nut). The system is quite heavy and very awkward to work on without a lift. A good!! muffler shop or M/B independent shop should be able to help.