About the only place your car would be really competitive would be DS (debatable statement). You would need to put your stock rear sway back on and put your grill back stock. Then you would need wheels that are stock size (dia. and width) and you can change the offset by 1/4" if you want.
The GR STi in STU runs a 18x9.5 and a 245 width tire with 140 treadwear. I don't know how that would go without the flares. You can also put on a downpipe and go stage 2!
The WRX goes to BSP in street prepared. Pretty much the same mods as STU, except you can run whatever width of R Comp tire you want.
You can modify your car however you want and just run whatever class you end up in, you'll still have fun. But if you want to be competitive I suggest you go to scca.com and
read the rule book. I just hate to see it when people blow a ton of extra money just to get an extra pound lighter wheel thinking they will be competitive when their car isn't built for the class they are in, or they have an uncompetitive car for their class.
Just come out and drive on your stock wheels and tires and see what you think. It will take a few thousand miles off of your tires, but you won't miss them.
