better to add an aftermarket sub amp and deck, or replace everything in an 02 maxima?
 

w/ bose sound system. I'm thinking the bose speakers are already pretty nice so I could just get new subs an amp and a head unit. Would that be possible though?? I'm only considering since the bose speakers are already very nice

Are they amplified? If so forget the deck, and just run a loc to an aftermarket amp.

Sorry to ask but what's a loc? And I think there is a bose amp included with the system. I heard it sounds a lot better with a new deck though since you can change more options than with the one you're given.

A loc is a line out comverter. It allows you to use stock deck with aftermarket amps. Put an a/m deck in if that is what you want. You wont have much of any other features if your speakers are factory amplified. If you really want something good and keep your factory sound and have all the sound control features of a deck., look into a rockford 360 or an mtx re-q. Or you can take out your factory amp and amplify your speakers off an a/m deck or an a/m 4 channel amp, there are many ways to do this and i am just trying to give you the most inexpensive route.

how do I know if the speakers are amplified? I've just heard that the bose system comes with an amp