Hi , I have a A3 cabriolet 1.6tdi Technic 2011, I have noticed that there are no rear speakers just a massive big hole that I would like to fill, now it's no big deal if I don't have rear speakers but if it's it possible and not some long winded job to do I would like to fit some, also noticed that there is no fader option on the HU (chorus) so that makes sense as no rear speakers ......I would like to keep the OEM HU even it meant a upgrade ,fcould anyone help...Thanks