Browsing ebay and look what I find...stainless steel replacement grills!
Obviously at $334 its a bit steep but...
http://www.ebay.com/itm/2014-TOYOTA-COROLLA-S-2PC-FINE-MESH-GRILLE-GRILL-E-G-/301246034773?pt=Motors_Car_Truck_Parts_Accessories&hash=item4623a9b355&vxp=mtr