My way probably isn’t cost effective for a big shop, but it guarantees the car can be replaced back to stock easily and everything works like factory with zero lights. My car is an A8 with the RF hub from an m6 (my entire car was an m6). Everything works like stock, I even have paddle shifters. Only thing that I don’t have is the remote start. All I had to do was replace wiring, reconfigure BCM, and have PCM flashed from m6 to a8 os. The m6 cars works out of the box pretty much with the TH400. When I did it, my rf hub read the config from the bcm - did not need to touch the RF hub. So, if you wanted to do the TH400 swap on an A8 - you’d replace headlamp to dash harness, engine harness, flash pcm, config bcm, neutral saftey to clutch master cylinder connector, and plug in the reverse lockout solenoid from a tr6060.