Just had my MMI stop functioning - only indicated "trying to initialise"! Audi Oxford wanted the car for a day and to charge around £600 for a software upgrade! - availability of service slot was end of October. Checked another forum: (e-tron) and someone there had a similar problem; held the radio button (by the gear selector) in for 30 seconds and this re-booted the system. It also worked for me! All working correctly so far. Others may have had similar experiences with Audi dealerships?