Hi, I have a 2011 Audi A4 B8 with an Audi Concert system and I would like to install an Alpine MRD-M1005 amp. The Amp does not have a high level input but I can adjust the line level voltage on the amp from 0.1V to 8V. Will I be ok with setting the amp to 8V if I use the original feed to the original sub?

Does anyone know the pin out on the original amp? I am after the line level in and how do I remove the connector? I'm guessing it has something to do with the purple lever.