I' ve had the magnaflow mufflers for 3 days now and I noticed they are really raspy when cold , but go away when they are hot. Anyone else noticed this? Also, they are pretty quiet and want to know how much louder they will get. Someone posted before that they get almost as loud as 40 series flows after sometime and wondering if anyone else and chime in on this. I hope they don'tl sound like glass packs when all the packing inside goes away.