Went for a drive, had the volume up at 24 - before when driving it was at around 16 (13 was when parked). Very clear sound, the mod has not introduced any extra noise. The volume goes up to 35, which I've never done before when music was playing, and now it is reasonably loud at that max level. Nothing earth shattering, I might have it that loud in rare circumstances (who am I kidding, I'm too old to want that).
But the hiss is so quiet now. Definitely less than 1/3 of the original noise. Very happy
