I'm not a body expert, but I don't see a problem with doing that.
My Legacy didn't have a hood scoop on it to begin with. My body shop cut a hole in the hood and stuck the hood scoop on. Ever heard of MAX POWER magazine (UK edition)? They always have cars with Impreza hood scoops on them like Honda's VW's, even trucks and they look good. I'll try and get a pic on my Legacy as soon as I can. It might be better if you email me and then I'll email you back with a pic. I can never get my pics to load up on this forum.
Email me at SWEETBOYREX@HOTMAIL.COM