i still cannot imagine maserati would have a 2008 MASERATI Quattroporte Sport GTS.
(i m in denial, as my 05 QP will depreciate even more if this is true).
i like to believe they have, but really, i doubt it. my reasons:
1) 500hp is in the territory of the 612 Scaglietti. (540hp) and very close to the F430 (490hp). it is even higher than the 8C (450hp) and much higher than the GT. is it possible they worked the current engine (4.2) or the 4.7 into 500hp for maserati?
2) this will very much piss off the buyers who just spec'd out a GT. they will feel they are 100hp short.
3) product planning - they just release the QP Automatica last year at 400hp. this will very much piss off all those new owners. they also need to show off their spyder soon.
of course, we can see on the other perspective that
1) 500hp is common place for M5 and E63. maserati was behind anyways.
2) the GT is a different car anyways. the owners might just need a four door

3) the QP Automatica owners are a different breed anyways (soccer mom??). they dont care about the hp, and they dont know how to work the DS anyways... and as well, it's about time to update the QP. the factory should be focusing on pumping out GT in fall 2007 anyways, so they can get the orders in for this QP GTS for spring 2008 as a 2008 MY...
well, all in all i think this rumor comes too sudden. ( one source, no where else from automotive journals, etc). does maserati have the ability to push out a 2008 MASERATI Quattroporte Sport GTS with 500hp and ready for delivery for the 2008 model year?
we will wait for the Frankfurt autoshow.
i think historically maserati likes to showoff new stuff at Geneva in March, and then production for the next model year. but the QP was debut in Frankfurt in 2003... so who knows. if there are really upgrades to the current QP line, i am predicting for MY 2008, a slightly restyled front and rear bumpers (as in those spy pics) and perhaps hp hike (470hp maximum, but 450hp more likely). i doubt the 2" drop.