Glad you posted again; I had already forgotten about this.
I'm showing the following part numbers for Korean-made Elantras:
52910-3X170 Steel, 16x6.5
52910-3X250 Aluminum, 16x6.5
52910-3X300 Categorized as aluminum, but labeled steel in description, 16x6.5
52910-3X350 Aluminum, 17x7.0
52910-3X450 Aluminum, 16x6.5
52910-3X550 Aluminum, 17x7.0
I believe they'll all have the same bolt pattern, but they'll differ in width, diameter, and style.