I'm looking to replace some of the speakers in my 2007 tsx and adding an amp to power the back 6x9s, or alternatively adding a sub. I have several questions: Will any 6x9 fit in my car? Crutchfield only has one 6x9 that supposedly fits. why wouldn't any 6x9 fit? it doesn't appear to be a mounting depth issue.

I want a more powerful and full range of bass displayed as well. I believe the 6x9s are filtered in the tsx so that they only receive bass signals. The stock 6x9s are 20rms and 40max. Would replacing the speakers with 6x9s that were 100rms and 240max and then pushing them with a small amp (~2x100W) make a significant difference? or should I use the amp to push a sub instead and leave the factory amp to drive the replaced 6x9s?

Final question: I would prefer to wire the amp without getting behind the head unit, but I'm not sure how to get an unfiltered signal to the amp? I'm pretty sure the remote can be wired off of the fuse that runs the head unit, but I don't know how to get the proper signal to the amp with all the factory wiring. Since the amp is being used to generate bass only I should purchase an amp with low pass filter, right?

Sorry for the lengthy questions. Any help is much appreciated.