Not all GT's in 2007 have supercharger, as many of the SE packages were pasted as GT, but were NA.

As for 2005, if its not a GTP, it's not supercharged. 2005 was also the only year of the GTP and GXP as model options. In 2006, the GTP was dropped.

Agree with above that if you found a 2005 GT with supercharger, its been swapped.