Adding a sub and amp to standard HU.
First time on here. Just after a bit of advice. I have a audi a4 avant 2006. it has got a 6 disc front loading cd/mp3 player and bose speakers (i believe they are as bose on speaker covers) and i am looking to keep the standard head unit and add an amp and sub to it for a bit of punch.
I am not sure how to go about this and have tried looking around to see if there is a simple clip to do this but no joy.
Any help on this would be much appreciated, even if you u can point me in right direction where i can purchase the wires etc.