No need to worry about immo on a 2000 S4.
Just get the cluster coding right, vag commader for mileage, and you're done.
You forget, not all S4's are in North America....
OP: If you live in Europe, or the rest of the world, swap the gauges, cluster, and the small pill inside the key into the other car. This can all be done via software, but that wasn't what you asked.