True, but you could still get a gt30 at that time. Larger injectors weren't all that much and a decent exhaust wasn't all that expensive. The only thing that would be hard to obtain would be an exhaust manifold for top mount gt30. Most of the work would be custom fab-Ed.
Like I said its mostly speculation as you don't know who would be buying the cars and what mechanical experience they have or don't have. In the eye of a consumer in 2003 more people would choose the evo just because of the "fun factor" you mentioned earlier. I like a car that serves more then just one purpose. I also believe they had a mr edition that was more of a track evo. One of my friends had one in high school, but idk of the add ons were mostly cosmetic or engine performance based.
Sent from my mind