MODENA, Italy — The Maserati Quattroporte Sport GT S will make its world debut at the 2009 Detroit Auto Show and shortly afterward will arrive in dealer showrooms in the U.S., the automaker told Inside Line. The Quattroporte Sport GT S will have a base price of $138,400, including a $2,600 gas-guzzler tax and a $1,800 destination charge.The Quattroporte Sport GT S is priced $1,000 less than the Gran Turismo S, which starts at $139,400.Maserati says the Quattroporte Sport GT S is designed to be 'a real driving machine in the guise of a luxury saloon.'Power in the 4.7-liter V8 is boosted to 433 horsepower. The front and rear suspension systems get stiffer springs and a lower ride height. Exterior cues include a new black grille with concave vertical fins with the Maserati trident logo, new headlights in metallic titanium finish, and black twin oval exhaust pipes. The cabin gets new M-design seats with perforated Alcantara and leather upholstery.The unveiling in Detroit will take place on January 12.Inside Line says: Maserati gets ready to rev up the Detroit crowd with some impressive firepower. — Anita Lienert, Correspondent