for serious i'm sure you can buy a WRX hood scoop, cut a hole in your hood and put the two together. http://www.horsepowerfreaks.com/partdetails/PIT/Body/Hood_Scoops//5993 something like that, hole, fiberglass, whatever it takes to make it look good.
for not serious, come on. are the headlights the same? are the fenders the same? is the grill the same? is the cowl the same? if not then the hood won't fit since those are the things that are going to determine the out line of the hood. and since they're body parts they'd need to be exactly the same so your gaps line up correctly. any small difference is going to be ugly because you're going to get some nasty gaps.
for not serious, come on. are the headlights the same? are the fenders the same? is the grill the same? is the cowl the same? if not then the hood won't fit since those are the things that are going to determine the out line of the hood. and since they're body parts they'd need to be exactly the same so your gaps line up correctly. any small difference is going to be ugly because you're going to get some nasty gaps.