Surprise surprise.... Prior to a 4 hour trip, I double checked the usual suspects (oil, coolant, washer fluid, tire pressure), to make sure I was good to go. Found the front right tire pressure was lower than the others by 4 pounds.
Apparently, the service departments "solution" was to deny they heard the noise, and lower the air pressure in the offending tire to make the tire soak up more of the "thump" to make it appear that it "fixed itself".
So when I put all four tires at 35 PSI, guess what? Thump-o-matic. Never been so disgusted with service departments in my life. Either fix the damn thing, or say you don't know. If you don't know, take my car, and rip it apart and fix the damn thing. Use your "gray matter" between your two ears and figure it out, THAT'S what you get paid to do, right?
**END RANT**