This car audio shit is making my head explode!
 

The problem is my budget. I absolutely need to keep my sub/amp/wiring below $200 total. The good thing is that (after exhaustive homework) that I'm going with an 8" downfiring in a box sitting on the floor directly behind my center console in the 4Runner. It'll be a .5cuft square that straddles the driveshaft tunnel... pretty straightforward. The amp will be in the back in a side console.

I've registered and searched at every fucking car audio forum and searched every thread in every forum with the word BUDGET in the title... and this is what I've decided on. Should be about $170 shipped for both.
http://cgi.ebay.com/MB-QUART-RWE-202-NEW-8-SUB-300-W-DVC-SUBWOOFER-RWE202-/130395739235?cmd=ViewItem&pt=Car_Subwoofers_Enclos ures&hash=item1e5c311463
http://www.woofersetc.com/p6418/Di30...-Amplifier.htm

I've already got MBQuart 6.5" components and coaxials in the doors, so I'm keeping with the theme... and due to the wife, getting an amp with a bass knob mounted somewhere she can reach is mandatory. Both of these units get great remarks for a clean budget setup that won't piss off the neighbors, but will impress the shit out of people used to "premium" OEM systems. I'll have a local shop fab me up a box and I already have some of the wiring... so it'll be like $225, but to go cheaper, I'd be buying Boss or Pyle stuff. I'll keep y'all updated.

Are you into SPL or SQ?

needs more parts-express.com and talking to y8s.

I know what I've bought. I was leaning towards a Alpine TypeR 10" and a Cadence 500watt amp in a wedge in the cargo area, but it would have been another $100+ when finished. Plus I like the stealth aspect... nobody would suspect to look between the baby seats for a sub. The floor is always covered with toys and stuff anyways... and it'll just be sitting there for easy removal. I'm also going to Y the speaker lines and run a second set to the cargo area if I ever transport 5 people and need the feet-room in the rear seats.

This setup is just to generiously fill out the bottom end for a better-than-stock setup. I'm a fan of quality over quantity if it really counts.

Brain, Dayton Quattros from PE also came highly recommended for a budget build, especially for SQ. I've DIY'd 2 home subs with Dayton stuff... but I like the idea of having all the speaks from the same brand, and the deal on the MB's is really good.

Other 8" sub-$100 subs considered:
Boston G2
Image Dynamics
Cadence
RE Audio