I have a 6 month old Q8, I also experienced the same issue of the nav continually rebooting. It then progressed to the whole system shutting down, no music, nav, aircon, phone, driving settings etc, just ignition, brakes and lights. Been with
Audi for 3 weeks, to date no estimate when it will be fixed.
Audi offered me a Hertz rental! To date no one has even offered an apology. This is my first
Audi, I also have a Porshe Panamera and Merc C300 Cabriolet.
Audi after sale service is appalling.