I have a 2015 Chevy Trax. Recently I have noticed that when the car is idling it smells like burning rubber and will only happen after about 10 mins of driving. Living in northern Ontario I warm my car up before I leave my house and no smell but i Drive for 10 mins and the smell will come when I stop at a red light or when in park. I have brought it to the dealership twice and they cannot find anything wrong with it. Is there cause for concern?