I know I've seen a thread on this topic, but can anyone tell me if you can or can't replace the speakers of the bose stereo to aftermarket speakers, relatively easily? I was just in my friends sentra spec V and it sounds so much better than the bose in the Z. Granted he had replaced 1 set of speakers and added a set of tweeters but the sound was soooo much better. It was really almost pathetic that this $18K car sounds that much better than a $35K car. Any info would be greatly appreciated.