[Aux1234]

If you go to navteq's website and search for an upgraded map for a 2005 A6 the website says, "New updates are currently available for your navigation system, but can not be ordered from this site at this time." A similar search for a 2005 A4 yields, "There are no updates for your vehicle at this time."

Didn't both the 2005 A4 and A6 have a RNS-E option? Shouldn't it be the same disc?

 

[AudiA4B6US]

The Allroad was the only A6 with the RNS-E. I think the 2005 A6 is already the C6 which comes with the MMI system.

 

[PetrolDave]

Didn't both the 2005 A4 and A6 have a RNS-E option? Shouldn't it be the same disc?

The MMI disc for the A6 won't work in an A4 version of the RNS-E, and vice versa (despite the A4 RNS-E saying "MMI" on the screen when you turn it on - confusing!).