The bottom line is this,
If your vechicle has a safety feature, whether it is required by law or not, and you disable it and then you kill a pedestrian with your car, you will definitely be opening yourself up to huge amounts of liability. And you will probably lose. Best case scenerio is that your lawyer can prove that the pedestrian was drunk or for some fault of the pedestrians, walked into the road and didn't look. Maybe you will only be partially liable. But that will still cost you immensely!
Worst case scenario, jail time.
A prosecuting or plaintiffs attorney would have a field day with this!!
The car I am buying has it disabled but I will be plugging it back in. I don't like the sound either but I know too much about liability and it's not worth the risk. I have too much to lose. I also worry about the limo tint all the way around. A lawyer could easily say it hampered my vision and is the reason I ran over little Johnny as he ran into the road after a butterfly.
Food for thought before you unplug.