I wrote this on some other Forearm...so I'll bring it here too

So I don't have part numbers but I can help you all locate them them on Monster Parts (shopgmparts.com)
You will need to select a 2006-2008 Pontiac Grand Prix
*Note: I did not get my parts from them (Ebay for me, except door handles), I am however comparing the prices between a 2004 and a 2006 and their is a dramatic price difference between the 2.

Driver's side vent
Insturment Panel > Instrument Panel Components > Air Deflector > Driver's Side
$67.20

Center console w/o display
Insturment Panel > Instrument Panel Components > Center Bezel > W/o digital display
$72.69

Passenger side x 4
Insturment Panel > Instrument Panel Components > Air Deflector > Passenger's Side
$29.35

Door handles with rings x 4
Front Door > Interior Trim > Handle Bezel > *pick your color interior* (ebony is grey, but really black ) > Obviously the more expensive one is the one you want
$12.24

Brushed Aluminum door handle inserts (this you will need 2 x Left and 2 x Right)
Front Door > Interior Trim > Pull Handle > Cover > Chrome Right/Left
$17.40

GXP gauges can be found on ebay.

There you have it....all the pieces that make the Chrome ring'd Interior

That will pretty much give you the interior of the GXPs, sometimes this stuff pops up on Ebay, I also have the Brake and Gas pedal from a GXP.