Its not called the GT assist package anymore. Just Nav package. The power liftgate is a seperate option as well. Mine came with Moonroof/Bose, Power Liftgate, Tow Prep, and Navigation.
I dont know how much the sat/traffic will be later. I think the trick is to let it expire and then they send you a very discounted rate to continue. That is what happened with my g35 and xm.
Cool, so the PLG is not a requirement. I would prefer the retractable cargo cover.