I recently noticed that I sometimes get a flatspot at around 5200 - 5500 RPM. I can't reproduce it everytime I go through this rev range, but it does catch me a out sometimes. Is there any advice on what this could be or could be leading to? I am due a service soon and will bring this up then but would be great to have some backgroung information if possible. 02 S3 unmodified. Maybe its complaining about it not being washed and polished for too long?