I'm replacing the 4.2 in my aunts '01 A6 after her timing belt blew on the freeway. She has an AWN, but I found an AUX out of an '01 A8 for about a third of what a bone yard will charge. I can't seem to find any info off The Google to see if they're compatable. I can reuse her intake, exhaust, etc. if I need to but I want to make sure there are no other obstacles that are too major to bother. I would have to make a long drive to pick it up so I can't really go look at it and compare.