I am the proud new owner of a 2013 Mazda 3 GX, But ive got 2500 worth of audio I have to move over. Before I start pealing it apart. Does the stock deck have outputs for Amps??? I require 3 sets of outputs (1 for the sub and 2 for my 4 channel), and I want to keep the factory deck. Also, does anyone know the speaker size, model, or power rating?. Is it worth running my 4 channel amp to them, or should I upgrade to match up to my subs sound.