I got my AVIC-D2 about 2 years ago (new) and I was enjoying it in my miata for all of this time.
Recently though I figure out it would make more sense to remove it and install it in my Audi (since my miata is slowly being transformed to a race car). I bought a 2 din adapter for the Audi (A6 '02) and a the right harness and I plug everything in. After installing the antennas and everything I decided to start it and see if it works but to my surprise the unit didn't start!
I tested the power with a multimeter and there is definitely power going to the D2's harness plug.
As a confirmation