the latest issue of the Britmag CAR features a test between the S6 and E55. There are interior shots of both cars and you can clearly see how monstrous the nav screens are.

it always trickles down.

Ok, but my A6 4.2 arrived yesterday after 5 months of waiting with all options but the nav system. I can take it now or wait until January until another is built. Question is, is the non-screen nav system worth waiting another 4 months for. Opinions?

Just since you are asking probably means you should wait and get exactly what you want. These cars are a lot of money. After driving one I know that if it was me I would take the one that was here.
I had some trepidation about ordering it on mine. Was it going to be the 8 track of the 90s? Since there is no large screen you won't be able to tell if it has it unless you are using it. It wasn't much more money so I figured why not?
Try some of the other dealers and see if you can get one sooner with the navigation. Check out the Bellavia site and others. IMHO

The insurance institute has just released some interesting information about the accident rates of vehicles with big beautiful color screens for their nav systems. Rates are similar to those where drivers are using hand held cell phones. Maybe Audi is on to something with their simple system?

Here's a link to the National Highway Traffic Safety Administration notice of a public meeting this month to look at telematics and their safety implications for drivers. These include cell phones, navigation systems and other emerging technologies. Should be interesting.<ul><li><a href="http://www.nhtsa.dot.gov/nhtsa/announce/meetings/19991015.html">http://www.nhtsa.dot.gov/nhtsa/announce/meetings/19991015.html</a</li></ul>

I've decided to wait for the car configured exactly the way I ordered it. I will post my opinion of the audi navigation system once it's here.