Did you find out what the issue was with the clunk?? Mine (2009 WK CRD) did it three times yesterday when I first started out on a two hour drive. It did it when shifting from 1st to 2nd during light acceleration. Then it seemed fine for the remainder of the 2 hour drive until I was home. At the corner to my house and then climbing the driveway, it did not want to go from a standing stop. It did go forward, but seemed to be slipping. The engine responded fine, but the vehicle did not accelerate normally. I have been noticing for a while a harder than normal shift from 2nd to 1st when coming to a stop for a number of months now.