i used the bonding glue stuff that came with mine to fix it down along with the allen bolts until the bonding stuff was dry then removed the allen bolts and plugged the holes to tidy it up on the inside,a few pics...
So no bolts huh? Liking that, I like this spoiler, but won't be drilling holes in my car to fit it, I'd rather do without, I think they look great without spoiler anyway. Does look good though that sprint jobby.