With bracket and wiring harness, if possible.

 

Bumperoo

 

Just a suggestion...
When I was redoing my stereo, I was looking to put one of the OEM subwoofers under the seat. Instead, I ended up getting two of the Kenwood KSC-SW10 powered subwoofers. They fit really nicely under the seats just like the OEM, but they have easily accessible remotes for volume and frequency, and sound a whole lot better than the OEM woofers. They go for about the same price as the OEM ones too (140ish on Ebay).

 

That's a good thought. I've been wondering how to best add a little low frequency response to my system. I had an Infinity basslink in my old car but the lack of a trunk in my new 99 OBS has me looking for a new solution. That looks like a decent unit, but this one has much better reviews on Amazon and ships for only $117

Boss BASS600

I don't follow audio gear trends, and my initial reaction is to be skeptical of this brand I haven't heard of (maybe because it sounds too much like Koss) but the reviews are plentiful and good.

 

That's funny, I was actually just thinking the same thing about aftermarket underseat subwoofers, and the first one I found was the Boss unit mentioned above.

I'm certainly not an audio expert, but I'm pretty sure Boss is considered name-brand (but probably on the low end of the spectrum). But maybe I'm confusing Boss with Bose? Haha..