Last week I could access my entire phonebook (iphone 3G) from the MMI. Now when I check my phonebook, it only shows my favorites.. Any idea why and how I can make it show my whole phonebook again ?

Thank

 

Try killing the BT link between your phone and the car, delete it all together and re-establish it see if that works.

 

Also check the configuration of the Bluetooth connection to the car. In your phone, go to:

Settings -> General -> Bluetooth -> Audi MMI ???? (press the blue right arrow)

At the bottom of that page you can select which groups get synced to the car. Maybe yours is messed up.