I have a brand new pair of 2009 CTS wipers I purchased and ended up not needing when the decision was made to buy a 2014 CTS. Here is what I don't get. The '09 GM part number on the '09 wipers are 15890062 and 15890064. They are about 21.5" and 18" respectively. If you put those numbers in an internet search they will be listed for both '09 and '14 models. So I measured my new 14 CTS wiper blades. They are 17.7" and 24.6" respectively. But drivers side is longer than '09's 21.5". The part numbers are also different, listed as #23144359 and #23144358. It looks like I could use the short one but not the long one that is 2" shorter. Anyone able to clear up this confusion?