Connecting RCA jacks to speaker wires

[red_si_in_jersey]

I just installed the Eclipse AVN6600 in my SI. I searched these forums and could'nt find anyone who wired up the speakers using the preamp outputs on the HU to the factory amp. It seemed to make sense to me so I soldered in RCA jacks to the wire metra wire harness and simply plugged them into the HU. The sound is so much better since I'm not going through 2 amps anymore. Has anyone else done this?

Now I do have 2 other issues....has anyone had trouble connecting the metra antenna adapter to the factory plug. I tried for 20 minutes and could not get the plug to slide in properly. Second, Has anyone been able to hook up the steering wheel controls. Eclipse has a plug for "genuine steering wheel control" with 3 wires on the harness. Nowhere in the manual does it state what the wires are for. I can probably just go purchase the PAC adapter but it seems pointless if I can just somehow connect the single factory wire to the radio.