I know this thread is about a year and a half old, but after reading it, I wanted to chime in. I'm also a WRX owner (2004) and I'm planning on some aero mods to my car, but I didn't want them to be ugly. I did some work in Photoshop to show what I would like it to look like.
There will be an upper and lower grill block that is made of Corocel (by Coroplast) that blocks about 75% of the openings. It may eventually be adjustable or even automatically openable.
There will be foglight covers that smooth out the foglight holes. I might cut out an opening and line it with acrylic so the lights can shine through.
Then there will be rear wheel covers, also out of Corocel. I may paint them silver to match. I haven't decided which look I like better.
What do you think?
Original
Front View w/aero mods
Side View
Silver Cover version - Side View