You might find it in Europe but not in the U.S.
Have you tried the UK webiste?
Try this as well.
it might bring you to the color that you are looking for.
http://www.audi-a3-sportback.com/audi_dna.html?id=112542

I have ordered myself a Quartz Gray A4 2.0T Q.
I have the latest Audi magazine with the A3 Sportback on the cover and it looks like the car is Quartz Gray. You may find that issue (if you don't have it) at your local dealer. Audi sent out a few to each dealer.

the pics aren't real. i do have the mag but there are so many other grays that one can't be sure that it is quartz, the same goes for some of the pics on the german and UK websites- but again they aren't labeled. i wish someone from EU could post a bona fide pic of their quartz car.

<center><img src="http://pictureposter.audiworld.com/76795/tt_quartz.jpg"></center><p>here it is in Quarzgrau Metallic.<ul><li><a href="http://www.germancarfans.com/news.cfm/newsid/2041008.002/audi/1.html">article here (German)</a></li></ul>

Last summer I asked someone at Audi to tell me what color these Geneva auto show cars were and was told they were Quartz Grey Metallic (check out the A4). In these pics it looks a lot like Avus Silver but I have that on my car and I think Avus is more bluish than the Quartz. So I think maybe these really are Quartz. They told me it was a new color for 2006. It looks like an excellent color. Can't wait to see it in person.<ul><li><a href="http://www.audiworld.com/news/04/geneva/pix/content.shtml">Geneva show cars</a></li></ul>

because my wife had a A4 T Sport in 1996 that was quartz , but I accept that it has not been available on anything for a number of years.
No pictures - sorry.
It is not dissimilar to the old Stone Gray metallic on the series 2 4000/5000s from the mid 1980s

it is very similar to Avus, perhaps a tad more silver. It's much much paler than the 'old' quartz we had on our A4 in 1996.It's going to be great for not showing the dust and light dirt !!!!