I know the wire colours on the g3, not sure about the g4.
You cannot tap into the lines before the RCU, because the RCU in the back effectively *is* the radio and the amp.
If you want both your best bet is to get a CD changer.
You cannot tap into the lines before the RCU, because the RCU in the back effectively *is* the radio and the amp.
If you want both your best bet is to get a CD changer.