Hey man, I'm sure you want the real stuff but when I ordered my roush chin spoiler they didn't send the hardware with it and being the impatient person I am I went to lowes and got all the hardware. You need u clips and bolts. Not sure what the sizes are for the gt500 chin but roush called for 1/4 in bolts with the u clips. Worked perfectly for me. Just an idea!! Good luck!!.
'Sally' 2014 Mustang GT 5.0, Black
Shelby GT500 Axleback, Res delete, Barton shift bracket.
United States Air Force