I hear ya and I'm glad you are enjoying your car, I absolutely hate mine. Not sure if it is because I'm way too picky or if my car just makes a louder thud than most.
I have driven 7 new Mustangs and 3 made no thud at all, 3 made a slight thud, and mine makes the loudest thud.
I used to go...
Mine has a pretty loud thud under normal driving but when running it hard through the gears it sounds terrible. I took a buddy for a ride when the car was new and ran it up into 3rd gear and his response was, "wow, that hits hard".
Mine had a new engine installed at 745 miles b/c the dealer...