I have 2 SA12s in my 08 Focus, stock alt, but I want more, I have a Skv2-2500 (2,900rms) and I just ran 2/0 OFC wielding wire throughout my car, I have a steady 14v. My next step is to get a Northstar SMSAGM220. After that I think I'll upgrade my subs. I know that I had a discussion about this...