My 2013 X5 had this annoying metallic rattle at low revs that drove me nuts for months. Two different garages told me I needed a full cat back system, which was way out of my budget. Then a friend suggested a Dubai BMW Exhaust Repair Center that specializes in German cars. The guy put it on the lift, found a broken bracket and a small crack near the muffler joint, welded both in under an hour. Total cost was less than 300 dirhams including labor. The rattle is completely gone and the car feels quieter overall. I'm kicking myself for not going there sooner. If your BMW has an exhaust issue, don't assume it needs expensive replacement. Find a shop that actually repairs rather than just swaps parts. Huge relief honestly.