I have a crew cab Canyon with the Bose system. After a few months I changed the front in dash speakers to 3.5" Infinitys for a nice upgrade to the system. Now it's a few months later and I would like to add more power to the system. It sounds pretty good with Pandora at higher volume levels but a little flat when the volume is lower. I think I read someone has done this same progressive upgrade but I cant find it again. Would I need a 4 channel amp to power the 4 door speakers and leave the fronts on the existing Bose amp? Would this require a 4 channel LOC to keep the fader working properly. Maybe a Kicker powered sub later? No trying to do anything real fancy here, but just looking for an economical way to get a little better sound. Thanks