From previously looking anything above ? x 9.5 won't fit at all. I haven't been able to verify if x 9 fit. Anyone else want to chime in?

 

I've been seeing Veloster owners with 18x8 and it fit but right now I don't know if 30mm offset would work.

 

Just put it this way 18x7.5 49mm offset is stock wheels 18x8 with 49mm offset will push out 12mm because .5" = 12mm.

 

this should help Online Wheel & Tyre Fitment calculator. Offset, Tyre stretch and Rolling Radius calculator