Ok, I have a kit car im building and considering droping a 4.2L audi motor from an s4, rs6,rs4 or posibly a 5.2L V10 if i can find one. The car will be mid engine with a 6 speed manual trany. I want to know what components i will need to get one of these motors running. I know they have a can-bus wiring system with several moduals? Do i need all of these moduals to get the car to run or will it opperate with out particular ones not installed? Do i need some of the sub system wiring? What engine and trans combo works the best? I preferably want info from audi mechanics or someone who has attempted and audi motor swap. thanks