I have a Borla S type cat-back on my L99 and I was afraid of the drone, but it's really not bad at all. The people that say that must be really picky or want a quiet cabin. I, for one, enjoy the sound of my V8
The only time you really get drone, like has been said before, is when the AFM kicks in. But even then you have to be in the exact right rpm range and be slightly accelerating for it to be really bad. When I hear it, I just give the throttle a quick dab and get 8 cylinders going...problem solved
