samuri jack wrote:I guess the only question i have left is the factory speakers, replace them and rewire with no amps or rewire/splice the existing speakers bypassing the amps? Please some reply would be appreciated thanks.
best option is buy new speakers and new amps for them, and removed the old amps, headunit, etc. these parts usualy go for a decent ammount online can can help offset the money you have spent on the new hardware. or leave em in if you're thinking of taking the amps and speakers with you from this nissan to another ride.
new amps + new speakers are going to sound 100x better than stock. trust me it'll be night and day.
however if you don't want to spend the $ i'v never once had a problem adding an aftermarket headunit to a nissan with BOSE before. I just hook it up like normal and it's fine.
good luck and let us know what you decide to do.
oh and you can get some good deals on amps and speakers. you could do you're whole car for under $400 and have some decent equipment.