I purchased a used 2015 Q7 3.0 premium plus (super charger) yesterday. Drove great on test drive and off the lot. Drove the hour home from the dealership with no issues (drove/sounded great). I dropped my wife off in front of our house, leaving the car running. As I pulled away from the house there was an unusual sound during the first 10mph of accelerating, then it goes away, until I come to a stop or slow down to around 5mph. Then I accelerate and the noise happens again. It’s almost like a vibrating noise but you can’t feel any vibration. Almost like the engine is working harder during the first 5-10 mph then goes away. Any thoughts?