i m assuming ur talking about the "bose" amp mounted under back dash?
If so,those things suck lol....prolly better off getting another amp and run all new wire.especially if ur gonna go with aftermarket speakers.
Still do the same as what was stated. Be way less of a pain for ya.
no not 12 gauge, if you had the wiring diagram (which have not found yet) you could bypass the amp right at the source, allowing you to maintain all your existing speaker wiring. Otherwise, you should run brand new speaker wires (no finer than 20 gauge) to all the speakers and bypass all the existing wires. PITA i know but its just a fact of life. Tracking down the factory wiring is much more time consuming and frustrating in the end..Unless you had a wiring diagram (hint hint)