I have had a clunk noise (like backlash in drivetrain) since car was new, leaving the dealer's lot with 7 miles on the car. It is most notable when the drivetrain load unloads downshifting from 3rd to 2nd (PDK), or driving slowly and lifting off the gas. The dealership said they did not have another PDK 718 to test to see if it's inherent in the car. The technician who drove it with me said it was most likely the "coast" feature. I don't think the Boxster has the coast feature because when you lift slightly on the gas pedal at highway speeds the RPM's do not drop as they would if they had this feature. If you put the transmission in park, get out and gently rock the car back and forth you can hear a very similar sound at the ends of the rocking. A very metallic clunking sound. Anyone else experiencing this?