I have 2012 Nissan Altima 2.5s and I want to upgrade my audio with some bass and louder sound. I read on Internet that Bazooka sub woofer is pretty popular right now, and shouldn't be too expensive. So I want to get that, and maybe some amplifier (any suggestions?) for louder sound. As I understood, my sub woofer and amplifier shouldn't exceed wattage of my factory speakers, it that right? If so, how can I find out what is wattage on my speakers? I already referred to car's manual and Google, but couldn't find any specifications on that. I am really hoping that bazooka sub woofer and amplifier will be enough to satisfy my need, and I wouldn't have to replace new factory speakers. Thanks for the help!