A few go wing spoiler questions

(thought I'd mention first that I don't have a spoiler-ready trunk lid-a p.o. simply drilled holes in mine and bolted the spoiler on).

the special nuts are just to distribute the force across the brackets, I imagine (just guessing- mine has the special nuts on it, but they're just up against the underside of the trunk lid, so they don't really have an advantage over regular nuts- they actually fit worse, if anything).
It looks on mine like it's just under 1 3/4" between the studs-hoping you mean on each mount, not side to side, but I can get that for you if you need.