I had a GTC SRi parked next to me last night and it was HUGE! It dwarfed my MPS! The 19 inch wheels have got 45 profile tyres which made the wheels look like they'd come off a tractor! It looks to me like they've made this car so that any wheels fit, up to 22". Wouldn't surprise me if people started fitting them. The SRi also seemed to sit far too high, it just looked like one of these cross over cars, like the Nissan Qashqai or Juke. They do look nice in the pictures though.
EDIT: From what I can make out in the pictures, the VXR appears to be wearing 35 profile tyres.