[82 Silverado 4X]

I really like all of yours but I wanted something a little less understated.
Instead of boxes that sit on the shelf I built corner enclosures for my Kenwwod 6x9's by using pegboard, 1x1 strips and acustical insulation. I covered the enclosures with the left over material from my headliner. I screwed the enclosures into the same location as the factory rear 4x10's. Then I cut another panel to go across the back of the cab between the corner speaker enclosures and covered it with the same headliner material also. Nice and clean but I still have a place for my ratchet straps, bungees, tow strap and the ice scraper. I already had 4" Kenwoods in the dash hooked to my factory AM-FM Cassette. I just added a 6 Disc Pioneer Changer under the seat and am planning on adding a 4 x 50 watt amp under the seat later.