6 cylinder and 6.0 liter GT models are automatic only.
GXP came with the 6 speed manual.
Here is what they (2009 G8 GT) are going for at the auction... gotta love depreciation:
12/09/09 SO CAL $20,750 20,874 Below BLUE 8G A Yes
12/09/09 SO CAL $20,500 21,059 Below GRAY 8G A Yes
12/09/09 SO CAL $20,000 30,272 Below BLACK 8G A Yes
12/09/09 NASHVILL Regular $20,800 17,335 Below BLACK 8G A Yes
12/09/09 NASHVILL Regular $20,500 24,016 Below BLACK 8G A Yes
12/09/09 NADE Lease $25,100 3,751 Above BLACK 8G A Yes
12/09/09 DALLAS Regular $22,500 8,393 Avg BLACK 8G A Yes
12/08/09 STATESVL Regular $23,600 8,833 Avg WHITE 8G A Yes
12/07/09 FAAO $24,400 7 Avg BLUE 8G A No
12/07/09 FAAO $24,100 8,373 Avg SILVER 8G A Yes
12/07/09 FAAO $23,800 19,352 Avg WHITE 8G A No
12/07/09 FAAO $23,600 21,876 Avg DRK GREY 8G A No
12/03/09 NASHVILL $23,800 5,207 Avg GRAY 8G A Yes
12/03/09 ARENA $22,900 15,560 Avg RED 8G A Yes
12/01/09 BALTWASH Lease $17,900 29,964 Below SILVER 8G A Yes
So that dealer's price isn't bad at all..