Quite frequently, the small amplifier for the 6x9 subwoofer in VTEC models fails, or people want to install the bracket and speaker into a non-vtec model but do not have the amplifier. For those looking to replace the amplifier or add the speaker, I found a small 25 watt amplifier inteneded for car audio use that is TINY and would probably fit in the stock location. As a bonus, its only $15. It would also work well for bass shakers if anyone wants to go that route. Just a heads up.
http://apexjr.com/new.htm (near bottom of page)