Boy, I don't know all of the differences, since I only have a GTS. But I think for automatic tranny, you get the "sport shift" on the GTS (allows you to control when the tranny shifts), and of course for manual the GT has a 5-speed and the GTS has a 6-speed (we're talkin U.S. versions). Most everything else is just cosmetic differences. I think the standard interior colors are different too; I think most GT models have grey, and GTS has black. Don't think you can get leather seats in a GT, but I might be wrong. GTS has disc brakes all around; the GT has drums on the rear.