I recently had my 2015 golf serviced, and mentioned to the mechanic how I had two cases where on start up there was some fluctuation in rpms 800 - 1200rpm then it would settle down after about 10seconds. It happend while I was still in park and once when in reverse. They ran a diagnostic on the car, but could not find any problems. Any idea why this would be the case. Should I chase this up with the dealer as the car is less than a year old and therefore still under warranty.