I'm currently looking into adding a powered subwoofer in the back of my renegade. I've already added kicker 6×9s on the 4 door speakers to replace the stocks. Has anyone else already done this with the stock head unit? If so how does it sound? I'm having a hard time imagining how you would hide the speaker wires to the head unit. Also having a hard time finding an entrance through the firewall to get to the battery. I've also heard this could possibly void my warranty. Has anyone else figured all this out? I would appreciate any advice or experience in this subject, thanks!