Just received my 12GB Mark 2 unit yesterday.

I am in just about the same situation as you. I have a 98.5 A4, but without the concert stereo.

I'm still figuring out what I'm going to do exactly, but I'm considering having a custom install done by AMS in Mountain View. (a co-worker has had 3 installs done by them over the years and been very satisfied)

Let me know how you end up doing the install.

DB.