Aviator, in case you haven't played with it yet, and didn't notice in the original pic, heres where the bolts are. On mty care they are about 12mm holes (estimated)
I would suggest wrapping the bolts on the spoiler with tape, because it'* a hell of a balancing act trying to hold the spoiler and line up the holes without dragging them across the paint.
And for the template, agian if it'* not too late, I was thinking some of the brown "craft" paper, and doing a rubbing like people do on tombstones. But whatever works best for ya, I suppose.
1998 SE Midnight Blue Pearl
Gutted airbox, FRAM AirHog, removed MAF Screen, eBay clear corners, extended brake lights
I'm so much cooler online