That should work good for someone looking for slightly more bass then the factory system provides. Unfortunately it wont clear under the seat as this car has a fuel tank under the front seats so the seats are rather low profile underneath leaving not so much space for mounting anything underneath.

 

Nice to see another old school IASCA guy here. Although I am new ro this forum, I am not new to the IASCA competition scene. I am currently a certified IASCA judge and have won and judged many IASCA competitions in Canada and the US.

Sorry to bring this off topic!

If you want a nice, quality sound as far as bass goes, a nice custom enclosure in the trunk area and a single 8" or 10" will be pretty sweet!

 

I had the Sound Ordnance B-8PT installed under the driver's seat of my Ford Escort until the engine blew, which is why I now I have a 2010 Fit Sport. You can pick this unit up at Crutchfield for $150 (it was $200 when I bought it)...

Sound Ordnance™ B-8PT 120-watt compact powered subwoofer at Crutchfield.com

As you can see by the 500+ reviews on this powered sub, it does a very nice job at filling in your existing stereo with some 'thump' considering its small size. I was very impressed with it. Unfortunately, I tried to put this unit under the seats of my Fit and it won't come close to fitting....it's 9 1/8"W x 3 1/4"H x 13 7/8"H. I guess I could install it in the hatch but I really hate having it exposed....I like original.

Just putting it out there as another alternative for a compact sub that unfortunately will not fit under a Fit seat.

 

I wonder if you could somehow French that thing in there where that random cubby storage in the back right side hatch area.