FWIW, the threaded studs on each side are for attaching the spoiler to the grill with a couple washers and nuts to hold the two together for assembly to the body. It keeps you from need four hands to assemble it. The remainder of the studs just go into the holes in the lower valance.

It took me about 5 seconds to realize this when i went to install my new spoiler onto the car.

I was able to source a nice spoiler and under tray for my car. The longest part, so far, was getting the old spoiler screws out of the body, as the PO had simply ground them off and painted over them. I needed a small needle nose vise grip to get up inside and grab the remaining screw shanks and twist them out.

The new spoiler and grill are attached to the car, i need to take off each tire/wheel off and get the sides of the spoiler screwed to the body, then attach the under tray. I don't trust the screw holes in the body the ground off screws came out of, so backup nuts will go up on the inside, thus the wheel removal for easier access.

Doug