Hi guys - apologies for this question as I can imagine it has been done to DEATH but I am new to this forum so just need a little guidance. I am jumping from a BMW M3 to S3 (2002 or so) & from what I can gather, I NEED to chip the S3 Also from what I have found so far, the best way to go is either a Revo or AMD chip (or possibly Jabba??) Just want to see if there are any noticeable differences between them? Was also planning on putting a new air filter on it....K&N all the way?? Also I am also looking at an unmolested S3 tomorrow - anything I should look out for in particular? Thanks in advance for your help guys!!