Not too sure about the existence of an XD grand prix, but definately came in XE. I started a tread on this, link is
XE factory turbo
I also have some of the intake pipes for the factory turbo, said i was going to get pics on the other tread but still cant get access to a digital camera.
Will post more info on them later, but im pretty sure the grand prix came in the xe's as a V8 replacement at some dealers, while for the XD's you could still get v8's.