The GT has larger wheels - that may help distinguishing trim levels if exterior pics are all you have. There are two rim sizes to my knowledge, with the GT sporting a 17" rim and the lower trims using 16" rims.
You got some awesome eagle eyes if you can spot the different between 17” vs 16” rims in pics.

I do understand there are some slight packaging differences from CA vs US. CA Sport trim do not come with CC and 16”, I think?. In the US, all 08-10 trims come with the same 17” style rim and CC.
For US models, here are some hints to look for if only going by, I assume somewhat wide view and not close-up, pics:
Blacked out headlight housing (HIDs) – Definitely GT
Hard to see but if you spot a black box on the windshield, just on top of the rear view mirror (rain sensor) – Definitely GT
You should be able to see the “perforated” leather on seats and door panels and not the 80’s print on the cloth – Definitely GT
LED tails – Either a Touring or GT
Moonroof - Either a Touring or GT
No fog lights – Definitely a Sport
No aero package (hatch spoiler, side skirts) – Definitely a Sport