Are you sure this is going to work the same for a Subaru?
Honestly this could possibly the dumbest thing I've seen anyway. You have to go through the process of making one, and acquiring a sensor anyway. All this just to fake you car into thinking it's working correctly? Why not just buy a full set and let the system do what it's supposed to be doing.
You leave sensors in your stock wheels, and then trick your car when your driving really expensive aftermarket wheels? How about protecting your investment. Dumb.