i would like to upgrade the head unit and replace the 4" speakers and maybe add a little bass in my 91 westy.. not for showing off, but for cranking tunes on the road trips.. im sure  alot out here have done this,  any pictures and suggestions would be great.. especially on how and where you added your subwoofer.. and how and where you ran the wiring.. thanks  scott.. 91 westy boston.