Hey B, welcome to the site...
You might get a better answer on the A/S3 forum, but just for info, not many people change the air filters on the S3, as the ones that are already fitted on the car, the standard one is more than capable of handling the power it puts out and a lot more. Also, heard the oil from the filters can cause major issues with the maf, so might not be worth changing it. Any reason why you want to change it???
Cheers
Nilz