Yep, a well documented issue on many vehicles the last decade or so. Thankfully the Gen 1 cars have this fix available 
Here is my thread documenting the fix on my 2012. Like the Voltec warranty items, this fix is not communicated very well between GM and the dealer networks.
http://gm-volt.com/forum/showthread.php?230313-Gen-1-wind-buffeting-kit-installed-Bulletin-PI0642
Here is my thread documenting the fix on my 2012. Like the Voltec warranty items, this fix is not communicated very well between GM and the dealer networks.
http://gm-volt.com/forum/showthread.php?230313-Gen-1-wind-buffeting-kit-installed-Bulletin-PI0642