I've searched all over for a fix to this and not quite there.
I've just purchased my first Audi and very happy with it. It's an A3 3dr 2005 facelift model.
I purchased the Connects2 Can-Bus adaptor with loom in order to install my Pioneer headunit and Parrot bluetooth. All well apart from the fact that the rear speakers and sub aren't loud anymore??? Also the rear speakers are very selective over what frequency they seem to be chucking out. I've checked the settings on the headunit and made sure the HPF and LPF are turned off.
The fronts are wired off the ISO connector and work supurbly. The rears are plugged into via RCA (headunit rear to loom which has RCA for fronts and rears). The remote is plugged in as well as unplugging it shuts the rear off completely.
All I've read so far is that I should re-wire my rear speakers to the headunit amp but it seems fairly long winded. Please help!