I was planning to use those, but changed my mind. First, I was concerned about self tapping the screw end. Second, the self tap end on any one I ever found is longer than you can safely install into the hole without punching out through the spoiler. I was going to hog out the hole into a conical shape and fill with epoxy, then screw in the cut off studs while the epoxy was still soft. But as I said, I changed my mind.
Original studs are 1/4" thread on both ends. so I think the wood screw end of the Ace Hardware ones is too aggressive for that small area. There's alot of tensile stress on that little part, even without enlarging the hole.
If you are interested, I wrote a long explanation of how I kept the strain off the spoiler about 4-5 years ago. Do a search. It was a little complicated, but it transferred all the strain from tightening the spoiler to the deck lid onto push-on clips I added to the studs.