I am wanting to add subs and an amp in my z without having to rip apart the whole car is there any way to hook up an aftermarket sub and amp to the stock Bose system either by splicing into already ran wires or any other way

 

You can either use a line out converter to change the Bose output to a useable input signal for the aftermarket amplifier, or you can cut open some RCA cables and splice them directly into the wiring for the flat signal directly before the input of the OEM amplifier.

 

Rip it all apart