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?
any sifu out there who know how to remove water stain from car widscreen 7 window glass???? :(
i hav tried using autosol,toothpaste & car polish as well but it didn't work :D