I have the original navigation dvd for my 2004. Do I really need to upgrade it to Version 4 or is it not worth the money ($150 to $200 for DVD Version 4)?

the 2005 version (I think 2005=2004 version). There are many more addresses that I can now access that I could not before. Many streets and addresses not available in the older version.

there was even talk of a version 5, which apparently was released late this past summer, but then mysteriously pulled, due to quality control issues. Anybody have a copy of this?

that I had bought for my 05 A8 and still have it.
V5 is much better than V4, database is way extended though that is all that has changed as far as the interface is concerned. The DVD updates the software, suggesting that there are changes under the hood.
I never had a problem with V5 in the 05 A8 and I have no problem with V5 in the new car. I have no idea why NAVTEQ no longer supply the V5 DVD on the web but you could try calling them.
As I say I have a spare V5 DVD and I would buy the upgrade again if I had the same decision to make.

cool! if per chance you'd be willing to part with a copy of a spare v5 dvd, please email me at rexdwilson at aol.com

e-mail me, please.

Has anyone confirmed that V5 will work with an '04 A8L? Seems that some later posts indicated that it wouldn't.