In this video I will show you how to take out the various interior parts you need so you can run your power and RCA cablesin your Audi A3.
This will be similar for other similar VAG vehicles including the MK4 Golf and Seat Leon.
This video is to give you an overview of what I have done, there are other options for running your cables should you so wish but this is how I have done mine to be mostly hidden.