I just bought a used 2006 A4. I'm loving the car right now and I've never had anything this nice. Anyway, I'm wondering what exactly does the mode and the button next to the volume control does? And does the car have to be equipped with certain options for them to have any functions? I'm asking because whenever I press one of those buttons, it just says no function. Can I set a function to it? I love cars and normally am not this stupid but the vague instructions in the manual does not tell me anything!

 

They're for with the bluetooth integration, to toggle into phone mode and I think the one by the volume is for speech activation, or something.

 

These are only if you have Bluetooth and/or Navigation. The mode button switches you between the radio display on the DIS and into you phonebook of your bluetooth paired phone. The button on the right is for voice command or SDS. If you have bluetooth only it allows you to use voice commands to dial and make phonecalls. If you have Nav you can also run it with voice commands.

 

If you don't have the options then they do nothing. Iv seen other threads complaining about this. Maybe they changed it in the B8's, I dunno.