I put Bilstein b16 coilovers on my RS3 after a failure from Mag ride shock, and springs snapping (pothole damage). Massive change in handling, and far better. Don't go cheap on this as a lot of people do. They are fully adjustable in height and ride quality. Get them setup by a garage and setup for how you want to car to drive and handle. Also look at some better wheels, stock wheels are cast. Have a look at forged and flow form wheels. The top mounts on these cars are next to useless, so expect them to be broken and can be changed. Be wary about going for track ones unless this is purely a track car, you will feel every bump in the road!