I had the car at the dealer yesterday for a couple of issues and mainly for an intermittent clunk sound coming from the rear,especially on bumps but unfortunetly could not duplicate the sound mainly due to the rain,but the good part was the senior tech is a buddy of mine and was able to get a fairly good amount of oil buildup out of the CAC which was a good thing,the great and important part is you can really hear those turbo's spool alot louder know,guess the oil builup really had an effect,cause even the throttle response is better,at just hitting 23k on her its a cheap effective preventative maintenance which many should consider.Z