Got a 2013 GS. Had Corvette guy say that it was a broken hinge location on door. Going to pick it up now. Will see if the 'new door' replacement will fix. This was just  purchased as a Certified veh. and the dealer made it good. Only 8400 miles. We will see.

Try to perform the "power window initialize" procedure found in the owner's manual.  I have a 2010 and it is on page 3-18.

Hi, My 2005 started doing that, I usually find that if I'm doing something different, it causes a problem. Mine was at the start of summer. I had been leaving both windows down. Just a couple of inches. for the heat. The first time was in the garage, opened the passenger door and went to close it and there goes the thud. Didn't think much of it at the time, small clinch, no big deal. I used the key fob to lock and unlock a couple of times. Then it was more and more a problem, happened at the movies, in San diego. So, I thought the only thing different was leaving the windows down just a little. So I reprogramed the doors for the window to go down and up just a bit. AND started leaving the windows up. Have not had the problem since. Not once.  But, that's my story, and it worked for me.