I just purchased a 2019 Charger GT last month. It currently has 1,200 miles. It has the V6 motor and 8 speed transmission. For the past 3 weeks I have noticed that when the car is restarted once the engine is warm, there is an audible "thump" in the rear of the car. It does not do it every time, but 80% of the time. Now I am noticing an engine chatter for 2 or 3 seconds along with the thump. I took it to the dealership today and of course it did not do it. Anyone experiencing this issue?