I've heard that the are used for venting hot air from the engine bay. Very cool and functional (pun intended). But then I was looking at the frame and paneling, and I don't see how it is possible. The vents sit right over and slightly behind the wheel well, and are placed over metal framing...
http://s4.paultan.org/image/2013/07/Maserati-Ghibli-00027.jpg
http://s4.paultan.org/image/2013/07/Ghibli_21.jpg
http://s4.paultan.org/image/2013/07/Maserati-Ghibli-00027.jpg
http://s4.paultan.org/image/2013/07/Ghibli_21.jpg