It's been a year-and-a-half since Maserati lifted the wraps off a drop-top version of its GranTurismo coupe at the Frankfurt Motor Show in late 2009, and now the Italians are getting ready to expand the range of the GranCabrio with the presentation of a sportier variant at the upcoming Geneva Auto Show. The new GranCabrio Sport follows in the footsteps of its hardtop sibling offering an improved