What are some of the details on the wheels?

As manufactured the Cobalt & HHR’s had 2 wheel patterns.  They were 4 lug X 100mm and 5 lug X 110mm.  Either pattern is usable on the GTX.  Both patterns are popular on many non GM cars, making it possible to select a very wide variety of wheel styles, and sizes.  As stated earlier, Berrien Buggy can provide front brake rotors drilled and tapped for either wheel pattern.