I am posting this as a review of a budget system I just installed in my daily (05 tacoma double cab trd sport) that would work great in the S. The whole setup ran me less than 300 dollars- I already had an alpine headunit from my last truck. So for someone starting out, this will run between 500-700 based on the alpine headunit you decide to run. The whole setup weighs less than 15 lbs.
I will start this off by saying this setup is not going to vibrate your internal organs, nor is it going to create annoying rattles. This setup is more for a clean quality sound (similar to the shaker 1000 systems in the newer mustangs +05) but it does produce a good amount of bass.

To give the speakers a little bump in power I picked up an Alpine KTP-445 Power pack. Simply put it is a mini amp that bumps the rms power of the headunit from 15 watts to 45 watts. It really helped to clean up the tones from the stock speakers- aftermarket speakers would benefit more from this. The best thing about this is it only weighs about a pound and does not require any extra wiring. It is direct plug and play to the headunit and is powered by the radio.
http://www.crutchfield.com/p_500KTP4...rch=power+pack

For the sub I picked up a Sound Ordnance B-8pt which is a self amplified (120 watt rms / 250 peak) shallow mount 8" speaker. I was very impressed with this little thing. For the size and the price it is a really great deal- plus it came with a 10 gauge install kit for free. It is too big to fit in the passenger compartment (under the passenger seat) but would fit where the spare tire was or in the tool tray. This produced a decent amount of bass (no vocals- I ran the rca cables through the subwoofer preouts from the headunit) The package with the sub and wire kit weighed less than 14 lbs.
http://www.crutchfield.com/p_777B8PT...Sound+Ordnance

So for anyone looking for a great quality system that isn't going to add excessive weight and will not empty your wallet, this is the setup for you. And doing the 6 1/2" speakers behind the seats wouldn't hurt either.
If anyone wants the actual dimensions of the sub let me know (rough estimate is about 18" L x 10" W x 5" T)

 

Have you noticed any increased hiss when between tracks? One of the reviews I saw said that the reviewer had problems with this.

 

i heard a little static between a couple tracks but I chocked it up to my old ipod (its about six years old) but it was not very noticeable and only happened once in a while. I was unaware that it had this issue so I will try and pay more attention and see how bad it is when listening for it.

 

my daily is also a tacoma. You have a great eye for cars

 

I needed something nice (i.e. import because mexican trucks suck (i mean "american")) and something that I could use to tow my S to the track.

 

and in relation to the hiss between tracks i have not noticed any since the first day I installed it.

 

Gonna try to revive an old thread.

Any updates on where you installed the SW?

In this thread, it was placed behind the driver's seat with seemingly decent results: https://www.s2ki.com/s2000/topic/921...b-8pt-install/

In this other thread, it was laid down in the footwell (I have my concerns for projectiles in the cabin in the event of a crash...): https://www.s2ki.com/s2000/topic/921...b-8pt-install/

Thanks,

 

I have one installed on my car behind the passenger seat. It provides decent bass, even with the top down and is really one of the best options if you're looking for a simple minimum fuss install. I slide my seat back to get out of the car, so installing it behind the driver's seat wasn't a viable possibility.

 

Thanks. Good to hear the bass is decent. Whenever I've tried to bring up this option to audio stores, it's immediately dismissed as "not good enough" before they proceed to sell me a trunkwell option.

 

Yeah, if I upgrade it'll be a footwell with custom box because I don't want to give up what little trunk space I have. It all depends on your definition of good enough is too. I like enough bass to round out the sound vs actually vibrating your fillings out.