I got my gasoline version a week ago and everything is great with the exception of two things. I got the P2 HK audio but the speaker in the rear vibrates. Pushing the speaker panel inwards eliminates the rattling. Speaking of rattling I heard what appears to be a lifter noise when the car is idling. The "clanking" gets louder and fades in a repetitive way, but it does not happen consistently. However, it was loud enough that the restaurant valet brought it to my attention. I have since checked the oil and refueled with Sunocco ultra vs. Exxon premium. Car only has 450 miles. Question- Are MB engines generally a bit noisy or should I be concerned? I had a 2010 FX35 with no such issue.