This weekend I had SPT cat back installed on my '08 STi. It's a third Subaru, where I installed this cat back. Previous were GD chasis.
I have to admit on GR internal drone is a bit too much. So I've started exploring on what to do next to diminish that annoying drone which gives almost a headache. One thing on my mind currently is using Dynamat sound deadening to diminish that internal drone.
Started discussion on nasioc, we'll see where it goes.