2004 Subaru Outback, LL Bean Edition

Does anyone know why this vehicle would make a loud “clunk” when making a turn or entering a driveway. It only does it seasonally. All summer it has been quiet and now suddenly the “thunk” is back. At least 3 different Subaru dealers have looked at it and no one knows what it is.

It sounds to me that the outside temperature is effecting something in the suspension system. I would try to determine what area the sound is coming from to help pin down the area to check. Someone outside listening while you drive up may help determine the area of the noise.