G-Series was conceived by Pontiac for naming all their vehicles.
That simply doesn't apply with some models: Vibe, Solstice, etc. Maybe it was a poorly hatched idea and they don't plan to continue, or they will make the changes in the future years to come.
Aggressive 2007 GXP Auto
Dec 4, 2006 through December 31, 2009
DDMWorks Race Backbone Garage opener integrated into header Side blinker/marker K&N Filter
Shorty Antenna Wolo BADBOY horn...fun! Engine fuel pump insulator
3 failed pinion seals...300+, 9,700+, & 12,636 miles
Replaced outside driver door handle June 2008
Canvas top replaced June 2008.
Gas cap replaced June 2008.