Neuspeed was restrictive when mapping for both me and another S3 owner. As I mentioned earlier, my stage 1+ was done with the smoothed but standard airbox in place. The well respected tuner said the airbox was holding things back a bit and so I went on the search for something that I liked the look of. He also said to avoid foam filters as if they are not maintained they can go dry and crusty and so little bits break off and get into the turbo causing damage. In my case that probably would not have happened as I keep well on top of maintenance. So I bought the Neuspeed. Not to be outdone, the Revo was getting good reviews as providing the best airflow so I sold the Neuspeed and bought the Revo selling the Revo foam straight away. Originally ran it with a green cotton dual cone which performed well and looked very good against my red paintwork. However, it turned a dirty yellow green colour so I fitted the Pro ram last year to smarten things up again. . The Revo foam would have been OK but I am always keen to do research and improve where I can to extract the max from the car. It’s all a compromise really, the VWR appearance is not to everyone’s liking but is quieter. The Neuspeed pipework is a bit narrow for a 380bhp car but is very well made and fits perfectly. The Revo flows probably the best but on some cars the foam filter rubs into the headlight. I even removed about 2 Cm from the end of the Revo pipe to keep my filter well away from the headlight.