I have a 2016 Craz that came from factory with two Roswell tower speakers. I would like to add two speakers to the tower. There are two more holes on each side with rubber plugs just to the inside of the current speakers. When plugs are pulled out, there are wires connected to them. I am assuming these are available for adding speakers. Can anyone tell me where the other end of these wires are. I am sure I will need to add an amp for the new speakers but I can't find where these are going. Thanks!