1. Don't waste your money on Bose. Might as well get all new speakers and an amp. Even though I pieced mine together, a component system with an a solid amp would have been much easier.
2. I have a powered Rockford Fostgate 300w 12inch sub and it booms very well for the car. It's not the loudest bass you can get, but it certainly gets the job done and shakes the car (not in a bad, lets rattle everyone within a 100 foot radius, kind of way)! I love it.
3. Oh I have no trunk space. Sub and Amp! :P Good thing about my powered, if I ever need trunk space, it all unplugs in 2 seconds and is Velcro'd in place, so I can have half a trunk if I need it. But you can always get creative!
4. With a minimum of an aftermarket HU, yes. With a HU and an amp hell yes. My sound is crystal clear and loud without distortion (Just don't forget to install your crossovers like me. Tweeters do not like the lows!
)
There are some great guys on this forum that will be happy to help such as bigaudiofanat. He gave me some solid advice and is an audio guru. Hopefully my amateur advice helped you out a little bit.
