We have the same problems you describe, the random stalling and the clunk. Our driveway is pretty steep so I never gave much thought to the clunk. It is much quieter when parking elsewhere, I always just thought is was the relieving of driveline stress. I don't think ours is repetitive like yours though, are you by chance parking on an incline??
Our VX has stalled on my wife 2 or 3 times in as many months, same thing. Running at temp, she comes to a stoplight and it stalls, but it will start right up and run fine. It seems very random, also on occasion at highway speeds it will give a little hiccup. I thought it was a tankful of bad gasoline.

Brian