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?
Hehe, went to kedai potong, so decided to take some pics for u guys. Wrote it for the US forum, just cut n paste for u guys here. And other sifus who got more info, please post it up :D