Well basically my car is under warranty and support for Infiniti vehicles is next to nothing here.

I am not happy with the bass in my BOSe system and want to swap out the sub or whatever is in the for smething better.

1. IS there a sub woofer component I can remove?
2. What type of speakers are in now - Bose or something else?
3. Can I retain the stock hU and cd changer?
4. Will I need new wiring for a new sub and speakers?

 

There is no subwoofer component in the stock system.

My suggestion, if you want to DIY.... Get a line output converter, splice it off your rear speaker wires(read directions), and use that as your inputs to an amplifier(infinity,rockford fosgate,kenwood,alpine, etc.).

Pick yourself up a 4080 box, and wire that bad boy up, and you should be right as rain...

Yes you'll be able to keep the stock headunit.

If you're not comfortable installing it by yourself, go to bestbuy, circuitcity, or whatever is around where you're at, and have them do it, shouldn't take long, and probably wouldn't cost more than $50 in labor.

 

Since you have a sedan and the Bose system, you do have an 8 inch sub in the rear shelf, but it is weak. You will be best served by disconnecting it (leave it where it is though) and install a sub and a proper enclosure with a dedicated amp. www.4080enclosures.com has nice sedan enclosures that look OEM (I have one.)

You can retain your stock HU. There are several threads about how to do it. The important thing to know is that you should tap into the audio signal BEFORE it enters the Bose amp, which is located under the rear deck in the trunk.

Since you will be adding a dedicated sub amp, it's not much more effort to get a 5 channel amp and amplify your front and rear (rear is optional) speakers and replace them too. Your sound will greatly improve.

 

There's a sticky DIY on this with a lot of useful details!