Riser block installation question..., drilled holes in the spoiler? Options

[AMCMoe]

Ok it seems I'm the only one having this problem...

Where the risers bolt onto the spoiler, does anyone already have the holes predrilled and have the metal threading in there? My spoiler only has the holes where it bolted to the hatch, not where the riser blocks bolt onto. So I drilled some holes in the correct place on the spoiler but I don't have a clue what to put in the hole to retain the bolt. I took some pictures, they're bad quality because its dark and I only had a camera phone.





If anyone can think of any suggestions besides going to a body shop it would be appreciated.

[AMCMoe]

Thanks! Those are great. I think I'm going to try the toggle ones tomorrow tomorrow since they seem to be the strongest and see how it turns out. On the side I didn't drill holes in I'll use some of those wood screws with silicone. I'll post pics with what I come up with.