Hello.I have an Opel Astra H GTC with CD 70 and am not completely satisfied with the sound.Now someone in the forum suggested me to run the original boxes via amplifiers to get more sound.I still have an old 4 channel amplifier and here in the forum is probably described how the cables are laid. Now my question is, where do I connect the cable, what goes from power amplifier to the LS front?Would not like to take off the door panel, she wants to later but I think it’s time to stop. I took off a mirror triangle and glued Alubutyl in.Is that right or do I have to stick it down through the narrow hole and the “back wall”?Now have several layers glued to the inside. Mfg -Trigger-