I would just clearcoat the area of metal that had the paint stripped off [apply with small detailing brush] and then wait for that to cure. Then you can screw it on, and you should be free of rust.

 

i put a gtu spoiler on my second gen couple years ago. i just positioned the spoiler the body and traced the bolt locations with a marker. not necessarily the best way but it worked. are for rust, i coated the bolts and holes with clear silicone and wipped off the excess.

 

When I put the spoiler on my 'vert, what I did was take some zip-ties (ok this sounds like a joke, just keep reading ok?) and made little T-shaped pieces by taping 2 together- with a very short base or center, and long "arms". Wire would work better though. wrap enough tape around the upright part of the "T" so that it fits the bolt holes in the spoiler fairly well, but comes out easily. Insert the upright part of the T into the bolt holes, in a manner so the "arms" of the "T" protrude past the edges of the spoiler. Do this on EVERY bolt hole. Position the spoiler where you want it, and tape down the "arms" of the "T" for each hole. Remove the spoiler and you have a marker centered where you want your holes.

To keep the holes from rusting... hmmm... primer, touch up paint, etc.

Brad