My 2016 F10 M5 came with the PDC installed Arkapovic mufflers. The car was a long time sitter on the dealer lot and I got my CA to give me great deal a couple of years back.
Fast forward to last week and the muffler starts making a horrendous rattle noise on cold starts. My wife has been on a 2 year tear with me on this car - she absolutely hates the muffler - her claim, it wakes her up in the mornings and is convinced our neighbors will report me for noise violations
So you can imagine her reaction to the rattles.
Took it to the dealer yesterday (Classic BMW in Plano TX) - the SA just called to say the flaps have gone bad and BMW wants to replace the entire muffler system - WTF I guess. Car will be in the shop for 5 days till they get the part in and installed. Will be interesting to see what I get back.