Friz you are right. I ve been back to my dealer and had it checked out. It's just a normal vibration. We compared it to the dealers demo and it had the same vibration. My car has -20mm and is extreamly communicative through the chasis. The demo had PASM, Aerokit + PSE. There is IMO a significant difference to the feel and character of the car with PASM it's like a magic carpet, you could feel the car pitching/floating from the front to rear. I guess you get used to the particular set up. IMO i think the -20mm is a superior set up, i know you loose some comfort over the PASM but the payback is well worth it. To me the -20mm is the best thing on this car. Ok the car is fast in a straight line but not scary fast, through the corners though this car scares the [censored] out of me. I just cant believe how it holds on and feels like its pulling you through the corner by the steering wheel.