Nope, tried it again today,still won't access so tried two other 4G A6's. Couldnt access either of those.
When I go back into channel 6 to read the code it has not been saved as 1 but changed back to 0.
Any ideas welcome.
Update - Installed AMI to Audi A6 4G chassis today with no problem getting into hidden menu, just did as before and got straight in.
The other 2 A6's still a no go.
They have been supplied with Aux input instead of AMI incase you are wondering.