No nav option yet. XM and bluetooth will become standard on 2009's. Memory seats would be nice, but not a deal breaker. I'll have to review if eth GXP gets them. Lack of HUD is the worst item for me, but nothing other than Corvette and outgoing GP have it, so I'll survive.
JHP are working on the genuine GM blue tooth(Holden Commodore blue tooth) to suit the 2008 G8, will know more in the next 2 weeks.
There is talk about removing the silly red oil & volt gauge and adding a GPS touch screen in its position with a different facia that will accomodate a common size GPS.