Had my 2005 A6 sport for a few months and am really impressed with the SatNav.
I've tried more recent SatNav DVDs but it doesn't like them, so I reverted back to the original with no problems.

After a Jet wash on Saturday it now says "Navigation Not Installed" and the DVD eject button in the boot doesn't eject.

Have tried re-booting the MMI (set-up, big button and top right button) and of course had several short and long trips.

Any ideas before a day off work going to a garage?