Originally Posted by armstjr

I have a 2006 Honda Civic Hybrid. I added a sub woofer box with 2 12"
Rockford Fosgate HE with a P5100 Amp that is 2 x 250 watts RMS. It
has TONS of bass. I have had the car since March 15th 2006. I have 20,500
miles. I have had the speakers in since June and have noticed to difference in my mileage. I average 50 MPG driving 65 mph on the highway (100 mile round trip to work everyday) Only thing I need to fiqure out is how to get the plastic rear deck lid from vibrating. With the bass turned up you cannot even hold it down !!! And no, I'm not a teenager. Just a 37 year old that like BASS in his music.

Originally Posted by lithosphere

I just thought I'd share this info with you if you haven't discovered the answer, I have the HCHII without Navi, however I have added an infinity 10" with a 2 channel Fosgate amp bridged (900watts), I am still using the factory deck that came with the car, unfortunately there are no pre-amp outs for the install of an amp, you'll need to purchase that piece seperately (futureshop has a few pre-amp out products available), I believe the wattage per speaker is 50 maybe less. I just use the amp to power my lil sub and a half cap to buffer the extra amp requirements when I need that little bass kick. Over all my system sounds nice but if I had an aftermarket deck I'd be rolling in the bass.....unfortunately I have to turn the gain all the way up on my amp just to get the nice little kick sound I'm listening for.

Anyways good luck with your search