This sounds pretty good... I'll get GT3 within the next week, and I think I'll skip racing this time, and get straight to the reason I searched for GT3 in the first place - hybriding.
Yet, I think we should have certain limitations each week - perhaps a certain drivetrain for each week, on top of the obvious power limit. It would we nice to have free choice, but it'd all get down two routes: 4WD Ultra-power monsters, or Rwd Less-ultrapower. Perhaps we should have certain requirements for the 'theme', with a certain shell to be used.
Example: Mini Cooper 1.3l body (the 'Shell'), max power is 700HP, drivetrain MR, oversized wide wheels 'required'.