Heres a VT/VX Manta Grill for sale at NVU and it costs $66: NVU, Genuine Holden parts to suit Holden Commodore VR,VS,VT,VX,VY,VZ,Monaro,Statesman,Utes and HSV I have had no experience with fitting one, so I will leave that to someone else to explain.
They are very easy to fit, i did mine myself. All that is required is a jigsaw and some bostic sikaflex Just mark out the cutout area for the grill to fit into around the factory black vents (make sure u leave the top section where the bar bolts onto the car). cut out the vents and sicaflex the new one in. heres a pic of mine, im selling the whole front at the moment,