I have 2019 Mustang Bullitt. I track it 2-3 times a year, just to drive fast, I'm not competitive. I've installed Vorschlag plates just to save some tire life. Also running 285/35 ZR19 square set up. Those are the only changes I've made. Now the car has a frustrating, "thunk" sound when I drive over rr tracks, pot holes etc. It's a 'heavy' thunk, big metal, not a light metal sound. Seems like the thunk is front left wheel, or now maybe front under the driver dash location? You have to drive it over rr track or bump at 10-15 mph to make thunk sound. At first I thought is was driver side, shock/vorschlag set up. Took it out made sure all was tight and reinstalled. Still the mystery THUNK is there. Now sounds maybe under driver side dash??!! I don't have lift. I've jacked up car, look around, tapped some parts with rubber mallet What's loose? The car drives fine, no problems. I'm guessing a bolt with two big metal parts needs tightening. Car has only 15,000 miles. I had alignment (-2 deg each front tire for track) and they said it wasn't ball joints. Anybody have any ideas or hints before I take it to the dealership? Thank you.