Speak to a reputable tuner - someone like MRC in Banbury will map the car to the specifics of its engine, not an off the shelf solution - one size fits all kind of thing. They can also talk you through other options such as DPF, Cats, Map, Exhaust, a whole pile of options and have a lot of experience in that engine and its evolution from A4 to A6 into the A8.
It wont work out much more expensive, were talking maybe double digit increase in cost
__________________
|