Normally sound accs shop will have contact, you can check with them... Many people will mod/upgrade proton car, other brand need to rely on technician's skill...
But why you wanna increase amp output? ICE modding?
Broke my front diff.. Anyone have it for sale? Or know where i can find it.. To those who is using rb26 rwd must have it laying around somewhere rite? Need it urgently.. Please help tq