FINALLY got my adaptor harness from Kufatec and installed it - the Nav looks great.
I have recoded the unit (it was an 8E0 unit) for my A4 Cabriolet to 0403113 (I have a CD changer, but no BOSE or anything else).
Though I can hear the nav lady fine, I get no sound from the radio, CD or MP3s! The volume symbol is there but with a slash through it (it sort of intermittently shows up the disappears). The weird thing is that while I was VAGging the stuff like the tyre circumference etc, the sound came on for a about two seconds and then went off. I was thinking it was just muted, so clicked the vol knob - but nothing happens! All I get is this light hiss (punctuated by the odd click when I am connected to the nav with VAG-COM). The CAN is OK - I get the DIS display, speed signal and everything else. The Nav lady's vol can be adjusted with the volume knob while she's speaking (and the unit can be turned on and off) suggesting the knob is OK.
Any ideas? This car will be a boring place with no sounds!!