I posted this once before, some time back, but have never really got to the bottom of it. Basically the voice-controlled bluetooth system in my A4 won't allow me to delete or edit any numbers.
I can store new voice-activated contacts using the 'store name' command, but if I say 'delete name' or 'delete phonebook' the bluetooth lady cheerfully says 'Function not possible'. There's also an 'Enter PIN' option, but I get the same response when I say that too.
To be clear, I'm not syncing the phonebook from my phone, these are purely voice-added contacts.
Worst case is there some way just to wipe them all, as I'm selling the car soon and don't want the buyer to hear my family & friends phone numbers (or some of my embarrassing name recordings!).