I un plugged my soundaktor today, I've had a few vibrations for a while and since learning about this device being basically a vibrator, I thought i'd try n see if removing it would cure my problems.
It did! All vibrations are completely gone now, the car is much quiter at a cruise and feels a lot more refined.
Even with a milltek and p flo fitted the car is now very quiet apart from a bit of road noise.
Its very strange putting my foot down with windows up, it sounds like a different car. I actually prefer it to be honest. If I want a lot of noise I just open the windows and let it in! Having a rattle and vibration free interior is amazing as it was getting very annoying.
I recommend trying the car with this unplugged as I think its unbelievable how much noise this thing makes!