Great! Just ordered mine - $115.02 on Amazon. Mostly good reviews on there too
EDIT: I put mine in today. It is on the slanted surface behind the driver's seat. Velcro works like a charm!!! (in fact, I gave up trying to take if off to have easier access to adjust the Low Pass Filter).
Installation was easy. The carpet seems to end just behind the seats where there is a little "lip". I was easily able to hide the wires by shoving them inside the carpet where the two meet. In order to do so I had to take off the plastic that is around the handbrake, which is only held there with one torx screw. Just make sure you have many sizes of torx screws and it will be a breez.
The only thing is that it sticks up about an inch above the top of the slanted surface if you are to use the velcro. If you are OK with drilling holes into your engine compartment you could probably use the corner mounts for a more flush installation, as some bumps near the bottom of the surface inhibit mounting right against the slope with the velcro.
Sound is great. The two little speakers the dealer put in with the Panasonic stereo really struggled to get bass. With the sub I was able to turn off everything below 125Hz on the two speakers and run the sub up to about 130. This creates a full sound throughout the range, and the tiny speakers don't have to work so hard.
While bass response is not panel-shakin' ghetto bass, it certainly makes drum'n'bass, techno, chillout, and industrial music sound really full, and you'll be suprised with how loud and low it hits. There is no way I would turn the knob on the remote level switch more than halfway because the bass will just be too overpowering.
CONCLUSION: While there are better options for a show car (and plenty of room under the dash to build a custom box if you want to do that), this little amplified bass box will probably get you the most bang for your buck, as well as your time and effort on the install itsself. Easy peasy, smooth sound.