With my Blazer I'm thinking of building the box with 2 10" subs, and 1 6x9 built right in each side.
I would like to build it fully self contained with the amp and everything, wired up with plugs so I can unplug it and remove it.
Although I don't know if you'd have the room in the extended cab S-10 for this.
My resoning for this is because I plan on taking the odd camping trip, or simular events when I need the extra space