My vehicle has the factory radio and speakers ('94 full size Blazer). It appears to be a showcase for queer speakers with it's 4x6 dash and 4x10 rears. My plan for now is to keep the factory radio (major issue to replace). A pair of 4" coax in the dash with 150hz Hi pass filters and drive the bass tube Hi level inputs with the rear channel outputs from the head unit. I can then use the front to rear fade to set up my soundfield. For the 4" coax, I have been eyeballing those BC4002 with the aluminum dome tweeters. I figure the extra brightness of the aluminum tweets will "bounce" off the windshield glass rather nicely to fall on my old deaf ears. So what do you think of my simple system?