head unit adapter

where can i get an adapter to add RCA Aux out to my head unit so I can connect an amp?

the only place to get one is thru the dealer if your factory radio is equipped with the accessory plug. You can also buy an aftermarket line-level converter at k-mart, wal-mart, radio shack, etc.. that you wire thru your existing speaker wires. most amps have rca and high level connections that you should be able to use, the sound quality just isn't as good.