From a quick search it seems to me like there is no real bodywork difference in 2011/12/13 models. The 2013 model seems to be out just recently, so I would not expect that from Hertz. More likely a 2012 or even 2011 model (don't know how long they keep these cars). Hertz Car Sales sells some 2011 models, so they are apparently filling up with new ones.

Ford specs say 9.7 cu ft for the luggage...

@:-) Hey just found a video - take a look at http://www.youtube.com/watch?v=PTM2BQdOt5M - you can even learn how to stow the luggage!

Btw: isn't a 24" suitcase already something like a carry-on?