Chirs, I run GP with a LP VW Rabbit GTI. It used to be an ITB car before I converted it.
All I did was a hotter cam, HD valve springs, 16v pistons to get the compression to 11.0:1 and slicks. I did re-located the battery to the passenger side, and removed all of the door glass, but other than that, it's still IT legal. No Lexan, no figerglass fenders, no flares, etc.