I have a 10" Kenwood SVC slim-line sub in a box built as per gmcyukondriver's specs, under the passenger side of the bench seat in my '97. The sub is rated for 600w, & I have a (claimed) 700w amp (real world=350w) powering it.
I also lined that box with 'Fat-Mat'. For what it is, that sub & box is really surprising!
It really helped to fill in the sound. The large amount of sound deadening in that truck made a huge dif. in the sound quality.
But, it's no match for the 10" DVC competition series (non-slim) in my '98. That truck has buckets & the sub sits behind the console. Dual Voice Coil, bridged, wired down to 2 ohms from a 500w amp is more than sufficient in a reg. cab!
When I got my '98, in the back of truck mags, I saw plexi-glass rear windows advertised & thought, why would anyone want one of those? Everytime you washed the truck or cleaned the windows, it'd be getting scratched to ****!
So, one day I'm out in the boonies, playing with the gain & other amp controls, dialing it in. Had it cranked pretty good! Stood back about 20' from the truck, and caught a reflection off of the rear window. Holy crap! The whole rear wall & back window was flexing back & forth about 3/8" either way!!! Yikes! Now I understood the need for a plexi-glass back window! That glass window was on the verge of shattering!
A slim-line sub under the seat is no match for that, but it is a BIG improvement over what the 4X6's & 6.5's can put out alone.
Don't know if I have before, but I'd like to thank gmcyukondriver for the specs on the box for the slim-line. I hate woodwork, (prefer steel!) & I never would of attempted building a box without his specs for that. It work out very well!