Thanks this is very helpful. Is removable if I change my mind down the road?Putting in acoustic fill works and it significantly reduces the sound level. Whether that level after is good for you after or not just depends on personal preference. I packed mine maybe 2-3 years ago and the acoustic fill has held up just fine and haven’t had to touch them since. I just carefully stuffed in several sheets on each muffler and that’s it, pretty simple really.