I have started building enclosures for the corners of the cab from aluminum.
I will be adding component speakers to these also! These will be fastened in-place by screwing or riveting them to the weatherstrip flange on the door-jamb, and believe it or not, I will be taping the other flange to the rear wall of the cab using sound-deadener...LOL!
I was originally going to use automotive structural panel bonding epoxy to secure them, but when I went to remove some of the sound-deadener to do so, I decided otherwise!!! I appears that the adhesive on the sound-deadener will work just fine.
Here are some pics of the panels that I built...
I then added sound-deadener to the back-side of them, and carpeted the fronts.
And finally installed the speakers & crossovers into the panels...If it ever stops snowing here, I will get these mounted into the truck!!!