These spoilers are supposed to be bolted and double sided taped down. When you purchase a new item it should come with the fitting kit which enable the fitter to drill the holes in the boot in the correct places. Because i bought mine second hand i didn't come with the fitting kit so the spoiler shop glued and double sided taped it down instead. But Im going back on monday to get it refitted because it isn't sitting straight grrr
I recon that one on there is a bargain if it deff comes with the extras (the fitting kit should include sti sticker, clips, double sided tape, instructions and a design sheep that shows hole locations)
good luck and keep us posted