I was a tech at Maserati, Alfa Romeo and BMW for quite a few years. It would amaze me how many vehicles would come in for a noise complaint where when I road tested it I would hear three other minor noises but not one like the concern. I always loved pulling cars with an ashtray full of change. That meant I would never be getting a noise complaint out of that customer. I had a Ghibli lease that was almost bought back for a rattle one time that we could never duplicate. We found the idiot owner was very tall and had the seats in such an awkward position he had to crank the rear view mirror so far to see out of it the mirror housing would rattle on it. We never duplicated it because the seating position was changed just to get it to the shop. Loved the GTS Quattroporte. Tons of power for a 5500lb car.