I am new to Audi, and came here in search of help for a friend who owns an 04 Audi A8 L. Originally I was going to test his air compressor for air suspension, however now his car does not crank at all. He has changed out his battery recently with an Autozone battery that has 950 CCA. Anyway i feel that the immoblizer is preventing the starter from receiving power. Another odd thing is the DVD/NAV/Radio are not powering up. So if anyone has some ideas as to what is the problem is my post in the general tech area posted on 4/14/13. I do alot of repair work on ppls cars so i know that this won't be my first Audi, and after working on them i may need to get one myself.