I love my Infinity sound system with the controls on the wheel and don't want to get rid of it. Is there any way to hook up an amp & sub box to the stock radio?[&:]

 

Yes you can. There is this thing called Clear Path. You hook it up to your rear speakers of your factory system. It will not change the sound out of your factory system but will add the pre-amp out puts that you are looking for. Yor local stereo dealer should sell them.